If nobody believed in superstition it would be unable to hurt anyone



Superstition is always based on fear of the unknown. This is most obvious in the case of the superstition of fortune-telling. It can only be fear that makes a person reason, "I don't know how what she said came true therefore she knew the future." It is fear saying this for it is not logical. It is an argument from ignorance.
And when the fortune-teller is wrong, the believer will say she miscommunicated what she saw. Or the believer will say she misinterpreted what her powers were telling her. Or that there is a mysterious purpose why the supernatural misled her and it was for the best. The latter excuse is why people can claim to see the future and still expect their client to believe their claims when they did not see their marriage break-up or the cancer or the bankruptcy of their company coming.
Religion and belief in God are to blame for the acceptability of the notion that failures are not failures but part of a plan so that even innocent babies dying in a plague only happens to bring about a greater good. The notion only leads to chaos. All sorts of charlatans encourage the notion in their followers. And it is lucrative.
Superstition encourages the fear it seems to deal with - it feeds on it. For example, if your community is suffering and nothing seems to get any better, you will feel that there has to be a supernatural cause. Perhaps some higher power is angry because girls have been having babies outside of marriage or because morning prayers are not being said. This can lead to the girls being expelled from the community. Superstition reinforces the fear and it gets stronger. It does more long-term harm than good.
The person who believes that walking under a ladder brings bad luck is a believer in magic. There is no difference between magic and superstition.
Magic believers and superstitionists are selective in what they believe. They may believe that the stars control all that happens on earth. Or they may think the gods do it. In the same way, the believer who thinks that walking under a ladder is unlucky may think that accidently breaking a mirror is not unlucky. The same refusal to be reasonable is to be found in the Catholic who thinks that God would not have spoken to the Mormon Prophet Joseph Smith but that God speaks to the pope. Its all bias. To encourage that bias would be dangerous. It fuels our tendency to prefer delusion to fact. It fuels our wish to be comforted by our beliefs and suppositions even if it hurts and sets bad example for others.
Fortune-telling is based on the notion that certain people have mystical powers. Sometimes the believer just thinks that its a case of like produces like. If you see a letter in your teacup you will get a letter. That is a shocking denial of what we know of cause and effect. Its pure superstition in its most blatant manifestation.
Fortune-tellers attract many people. Strangely some sceptics of the supernatural pay a fortune to go to them. 
If any clients believe the fortune-tellers have powers, I'd be surprised. Surely they would fear somebody who has the occult means of seeing what is in their past and present and future? The seers could divine the most private and embarrassing things! The clients really want somebody to talk to and are engaging in fantasy though they won't admit it to themselves. People like to be told that there are good things coming to them - even if they know its not true.
Fortune telling is not just about predicting the future but can encompass telling what is going on in the present and what has went on as well by psychic means.

Tarot cards each have different meanings. The card layer will pick whatever one seems relevant and which feels right.

It is magic power that supposedly acquires the information that is learned through the tools.
The seer may see pictures in the crystal ball which she or he interprets if they are symbolic.
Some fortune-tellers use no props and call themselves psychic-counsellors. This is very dangerous. Counselling is a huge responsibility. No counsellor has the right to reinforce his or her suggestions by saying they came from a higher source. Counselling is based on naturalistic thinking - you experiment to find out what works and you keep it mundane and keep magic out of it. And what counsellor can be sure that the psychic advice is really coming from a good source? Most psychics today focus more on counselling skills to get results and they hope that the client will not notice how much the natural and the mundane have helped them. They need them to attribute it to the magic.

Does it make sense to say that the magic will tell you what is going to happen instead of limiting itself to making a better future for you? In other words, magic would cast spells to help you but does not tell you the future for you don’t need to know it if you can do spells to make it good.

Fortune telling and magic depend on one another and yet they are in conflict so even magic testifies that fortune telling and itself is superstition! Fortune telling would be evil for black magic when it centuries on knowledge and not on bringing blessing on you or others. Fortune telling is a denial that we always seek out what is best. It cannot work for the card-reader will use any magic she has to better her or his own future and not that of the querant. Self-preservation is our main concern.

If fortune-tellers really can see what is in store for you then they are playing with evil forces because the forces work in defiance of the ego. These forces will get you in some way at some time and perhaps unknown to others.

Fortune telling is bad according to the philosophy of rational self-interest.

Some psychics even claim that the future is in the cards or whatever is not laid down by fate. It can be avoided. It just shows what the trend is in your life and warns that you can change these trends anytime. So you can make it all up and you have the perfect excuse when the predictions fail to come to pass. Fortune-telling can only be superstition if that is the case for anybody can tell you that you have this trend in your life or that. Then there is no evidence that it can.
There is no free will so the predictions would infallibly come to pass if they really were insights into the future.
Not all fortune tellers are said to be deliberate frauds. Is this believable? All fortune tellers say that there are times when they cannot get anywhere with a client so what do they do then? They must just make it up. Actions speak of what you believe more than your words. It is easy to think you believe you have powers when you know fine well you don't. If fortune tellers really believe in their abilities then why do they not take more risks with their predictions? Ann has money missing. The fortune teller will say, "I see that the loss of the money seems terrible. But you will get money. Just be patient and it will work out." Why doesn't he say, "Your husband the bastard stole it"?
Even if fortune tellers are not all deliberate frauds, having anything to do with fortune tellers is putting people at the mercy of those who are knowingly fraudulent and who are just in it for the money.
Suppose you were involved in a relationship and thought that it should become an open relationship. There are risks with open relationships. If you felt you had a psychic sense telling you it would turn out reasonably okay you will go for it. What if your relationship collapses? You will then say that it was for the best and that the psychic guidance was still correct. Trying to use psychic powers will encourage you to take dangerous risks and you will never allow yourself to see through them and recognise there are no such powers.
Encouraging psychic powers and fortune-telling for fun makes people feel less bad and less weird for taking them seriously. Fun or not, it is publicity and advertising for the activities of charlatans.