I do think that many overcharge relative what they do for it. Mine (in a very expensive city) charged $180 and $200, and that was on the lower end of their sliding scale because I was not willing to pay more. Mine did quite a bit of extra outside of the 45-50 mins conversation once a week as they interacted with me quite a lot via email between sessions. But so do most professionals these days, communication is constant in many jobs. It is often said that being a psychotherapist can be emotionally very stressful and taxing, but so are many other kinds of work in their own way. And I think many professions definitely require more involvement and actual "work" done than a psychotherapist's. I know that my Ts like to constantly educate themselves, read related materials, one of them also publishes a lot of online therapy-related stuff, but so do many people, especially if self employed, to keep up with demands and attract clients. I agree with luc's note that there is unequal and disproportional distribution of income in many professions but, after all, those that can pull off high incomes do so because someone is willing to pay. I think that psychotherapy, especially private practice, is a sort of luxury thing with a certain kind of clientele, like spas. But if these is need for it, if clients pay that sort of money, why wouldn't they charge it?

As for what drives people to the profession, it may vary a lot between locations and cultures, but where I live, the compensation certainly tends to be a major attraction. I heard this from quite a few therapists directly. I do not feel that's a problem - there are plenty of professions and jobs people go into for the income as a main factor. The problem, for me, is more that there are so many bad, unethical, narcissistic etc Ts that collect the money and take advantage of or directly harm vulnerable clients in return, don't even make much effort to do a better job or to really try to get to know clients individually and to adapt to their needs. But such sharks exist in many other "high profile" professions as well. To the point of the OP, I definitely do think that teachers in general invest more into their work than therapists and often do not receive the appreciation and compensation they deserve. The work of a therapist is also very mysterious and hard to measure quality and outcomes yet many display attitudes as though they were somehow superior to ordinary humans and demand to be treated and compensated accordingly.