I think you overstate the case. Yes, everyone will choose a better option at no cost, but most everything has cost, and we have limited budgets of discipline, money, etc. to pay the various kinds of costs required for good things...so when someone "doesn't care", it literally mostly means that they won't pay the cost of the thing.

So, I don't really find it far fetched that quite a few people by a reasonable definition "don't care", by which I mean they don't consider the benefits worth paying much cost at all, which I consider a fairly reasonable definition of "don't care." I'd like to know Sanskrit; if I could take a pill and know Sanskrit, I would. But do I really care? No. I won't pay my time and attention for it. It'd just be neat. Mostly, too high of an opportunity cost to spend the time on it. The same applies with body shape for me. It'd be nice, but it's not worth my effort. I won't pay much for it, so "I don't care."