I also went to an ivy and echo this comment. The math classes were geared towards people who had considerable expertise / interest in mathematics to begin with, which didn't help someone like me who didn't have that expertise. While I think that academic settings that cater to advanced students are worth cultivating, I don't think intro or require math sequences are the places to do that.
I'm torn because on the one hand I don't know how someone who hadn't already been programming for years, or at least been a big computer nerd and tinkerer, could have gotten through even the relatively weak CS program that I did. I gather math is similar.
On the other hand, I don't think anyone expects to start learning, say, music, in college, and major in it, having had nothing but maybe a couple required and non-rigorous music classes all of k-12, and not being able to do much more than squeak out "Mary Had a Little Lamb" on a clarinet. Their first class will be them in a room of 19 others who have all been playing at least one instrument since they were 5, played in jazz band in high school and picked up tons of music theory, had extracurricular instructors and tutors for years, et c. Of course that's not going to go well.
Maybe colleges should just be more up-front about that, with other majors.
OTOH I don't think social science classes do this. They seem to assume no more than that you weren't asleep during your high school social science classes. They do expect you to come in writing at at least a 12th grade level, which is sometimes... optimistic. But not much else.
CS/programming (yes, I know they're not the same thing) is something of an odd beast at many top schools. I took MIT's intro MOOC a while back. And the idea that I could pass that, alongside other coursework, never having done any real programming boggles the mind. Yet, no other engineering major has that degree of informal prerequisite. And, yes, it's pretty much like the arts.
(As a side note, I did take an Intro to Music class in college. Of course, I discover it's taught by a rather well-known choral director so the class is filled with people who were quite practiced in music and said choral was happy to teach to that level. I actually got something out of it but a lot was also over my head.)
(As another side note, way back when I took intro to programming--or whatever it was called--for non-CS majors. This was back before PCs were widespread and I'm sure anyone here would find it ludicrously elementary for even an intro course at a good university.)
My university much preferred people who showed an aptitude for mathematics to people who had written lots of programs in C when doing admissions for computer science. Having done lots of programming before wasn’t really considered necessary.
Also went to an ivy and found the "math for non-majors" to be pretty well taught & very manageable - although I did have pretty solid high school math.
I did not have the same experience with my first physics for majors course - which was taught by a guy who talked into the blackboard and spent the entire class writing on the board in a fugue. Made me switch majors.