Dittoes. Math isn't just hard for many people to learn, it's hard for many mathematicians to teach--
I think it's discouraging to hear of some math classes taking pride in the number of dropouts. I'd rather hear of a math department at some university taking pride in the ability to teach the subject in such a coherent and diligent fashion that even people not extraordinarily talented could learn.
Talent in teaching math is much scarcer than math talent, per se.
I've often heard college student complain that their teachers not only were incomprehensible, but couldn't speak English well enough to be understood.
The number of dropouts from one particular course isn't because of poor teaching, but because of the nature of the subject matter.
We're talking about a highly abstract course that's all about proving arcane theorems and no applications. I didn't go to Harvard, but my college had a class just like that, and I tried it. Believe me, it's not for everyone. Most people, even many geniuses, will not want to take a course like that. This is a class that's only useful to you if you want to spend your life proving very abstract theorems that only a handful of poeple in the world could come close to grasping.
It's completely unnecessary even for most physics majors. Completely irrelevant to engineering. It's necessary, and appeals to, only a very small percentage of people. That's why the dropout rate is so high.
Most people who need to be good at Math should take the Calculus sequence for science and engineering majors. That's more than enough for 99.9% of quantiative career paths.
A lot of kids who are good at Math take this class to see whether the super abstract stuff is for them. They find it's not, and they drop, and it's good that they find out early in their undergraduate experience. Most will go on to very successful careers that involve application of math.