You don't think it's a given that, on average, students who
choose a degree that requires "heavy duty math" enjoy it more than students who choose a degree that doesn't require "heavy duty math"?
I'm unsure of the motivations most people have in choosing majors. When I see generalizations of a very large group of people, no matter how obvious it may seem, I just like to see data to back it up.
I chose CS after my university cancelled its computer engineering program. I chose computer engineering because it was a challenge in a way that english and history weren't. Much of my childhood was spent with my nose in a book because it was a way to avoid dealing with the religious schism in my family. As a result, my ability to read and write for an academic setting (and on standardized tests) made getting high grades a trivial matter.
I would change your assertion to "choose a degree that requires heavy duty math and succeed/graduate". Sampling after the choice is initially made is clouded by kids choosing what is popular and/or being forced to go to college because of social pressures and/or choosing only what will hopefully make them the most cash.
Given my science background, very little is a given until I see data. CS people get on their soapbox and talk about being superior in logical and rigorous thinking and then lead off with statements like it's a given.