Well, I'm just saying that the number of people with the enthusiasm to really, deeply grok, say, the PCP theorem, Bayes nets, or the FFT in their spare time is quite small. Sure, undergrad CS is just a "warm-up act for the real thing", but a solid grounding in all those topics is a really useful thing for someone planning a career doing technology startups.
"but tackling true CS subjects individually is not something a lot of people can truly do"
Unless they have jobs.
Please don't kid yourself into thinking that CS in college is anything other than the warm-up act for the real thing. It's strictly optional.