This is exactly what I thought 3 years ago when a dentist told me that it was very important for me to get rid of my wisdom teeth, because loss of enamel meant that they were very likely to decay quickly even with proper hygiene. Other dentists told me that it was not necessary, and could be done later if the teeth ended up decaying too much.

Now the teeth are completely decayed, I've started to feel severe pain, and since I've developed severe thrombopenia (<20 G/L), I can't get them extracted easily (couldn't find any dentist willing to take that risk), so since six months, I have to take anti inflammatory drugs for the pain and antiobiotics to limit the infections, as well as the folic acid and corticosteroids needed for ITP, and I have no idea when will this end.

It's very difficult to differentiate important advice from "easy money" advices, especially when this advice stems for a principle of precaution. Most peoples don't develop severe ITP, but if they do, getting wisdom teeth removed before they can cause problems can be very important.