The people who think that they can change their DNA are people who have not learned or taught themselves in depth, so do not be so short temperted or have short patience with them. They will learn, but in time.
For one, children living in fantasy land who do not have a proper understanding of how the laws of nature work, or even basic science for that matter, who read too much fantasy and fiction and watch too much tv. These children often pretend to be characters or creatures because it is fun for them and something to do. In general, such things can be ignored as nothing more than kids being kids, but only when it becomes a serious problem should it be addressed.
A second way to look at this is from a psychological standpoint. Sometimes children have very bad home lives and desire to become a creature they deem as stronger than they are now in order to escape or overcome their current living situation. For example, a child wishing to become a werewolf so that they can stand up to bullies at school. The desire and desperation to escape from this problem would make these children seek out spells and magical potions from books and online in order to make this a true reality because they vehemently believe this is the only way to fix the situation. This is why people who make wild claims should be talked to over attacked in chat. You never know how rough someone has it, and maybe claiming to be a werewolf is their way of trying to reach out and get help.
Either way, the best thing to do is to ignore people who pop into the chat and on the forums claiming to be a werewolf or other mythical creature. Only if the person making the claim becomes agressive in chat (cussing, spam, name calling, attacking others, etc) should a moderator's attention be gathered. Generally, if they make the claim and someone tells them otherwise, they'll go away or try to understand why it isn't real. It's nothing worth getting upset over, just ignore it and let people believe what they want to. As long as they are not putting themselves into danger or risking someone elses safety, then don't worry about it.
Ok, I will provide an answer. Some of us have felt a pull in this direction our entire lives. It is not necessarily an idea of a diseased mind, nor brain. The truth is, you are a skeptic, and that is a good thing. I am also a skeptic; though, with more faith in it than you...no offense intended. The truth is that we are human beings.
Well the spells that are fluffs are mostly under the fantasy section but for those who aren't they can easily be labeled as fluff, for example if the spell says do this on a full moon and the next day you will be turned into a werewolf, then that is a fluff spell. However only the site admin can delete them and he doesn't have enough time to go through them all and delete the ones that are fluff. The privilege of deleting spells was given to people but it was abused. So you should use common sense, maturity and intelligence to pick the spells you want to do.
And sometimes they aren't children at all, but adults with mental illness that causes them to believe that things happened that did not. Certain forms of severe mental illness can cause such delusions if the individual doesn't take medication. I had a roommate once that had schizophrenia and without his meds he would tell very very tall tales that he believed entirely.
Bottom line is, we really don't know these people and why they do what they do. Each may have a very different reason and we try to keep it as controlled as possible. But since we are on the first two pages to pop up on Google when the word "spell" is involved, it tends to create a lot of traffic--bad with the good.
If you want a more controlled experience within SoM, I suggest that you join a coven that doesn't automatically accept all requests but individually allows each member in after interview. Then you can be surrounded with people that are at least on the level.
to be honest. i believe that as humans we are always seeking improvement. even though some wanna do something crazy, or dangerous. but that is their decision, and i respect their choice. i am sorry for stating my mind if anyone doesn't approve.
The important thing is to provide them with the facts about magic and hope they take the logical steps to learn fact from fantasy. Can I say Vampires, Werewolves or anything else do not exist? No. I can however say there is more evidence to suggest that it is pure fantasy and little to no evidence to prove otherwise so I will not waste time on it. Further there are absolutely no known ways to trump science and magically change forms. Leadership by example and a few will self delete, a few will stay in fantasy land but a few will start to learn, respect and practice real magic. Do I think fluffs are insane? No. I believe that they are illogical but that can be changed. :-)