Yep, definitely, sure, you're right: you could definitely learn everything you would in college on your own.
But you won't.
I hated school before I reached the university level. I maintained good grades but I was usually bored and learned most interesting things on my own. A university was the first place I found a majority of fellow students who were straining forward to learn due to interest in what they were learning. It makes the experience far different from being with people who are just being goaded forward by a teacher or evaluating everything in light of "will this be on the test?"
Intensified credentialism has the effect of diluting classrooms that could be engaging with a bunch of people who are just XP-grinding to level up to a job in 4 years. I do feel bad for people who are there due to distorted economic incentives rather than genuine interest. I also resent them for polluting the intellectual environment of students who are actually interested in the material.
> I also resent them This was the absolute biggest problem I had in University.
This is not usually very hard to check, depending on the sport. Professional athletes at specific positions have fairly specific body types that enable them to succeed. Ask them what sport and position they want to play, and check their body types against the prototypical player at that position.
They'll always be able to point to exceptions - someone who had ridiculously high physical coordination or work ethic, but those traits are often more obvious than physical traits.
Yes, and my sort of utilitarian calculation is that you'll do more good in the world by discouraging a few would-be exceptions while not misleading a billion kids who obviously aren't going to be a professional athlete (or an extreme autodidact, or a Supreme Court Justice, or anything else like a handful of humans can do that the rest of us can't).
The truly odd thing about a forum like this one is that some of the people here actually are truly exceptional, one-in-a-million talents. I'm not talking to you :)
Anyway, my hypothesis (similar to yours, I think) is that those one-in-a-million talents receive a lot of reinforcement that they're one-in-a-million talents, already. They don't need it from me.