Much of our life in society seems to centre around democratically-actualized rights and customs. This is because abstract concepts like rights or customs require either brute force or general acceptance (respectively) in society, to be actualized. Saying something like ‘I don’t care if everyone does that, they’re wrong, gets you about as far as does saying ‘gays ought to have freedom in Muslim countries’ so long as you don’t have either brute force to uphold such rights or general or some localized social acceptance to uphold the alternate custom you advocate.
That’s why it actually does matter that for example most guys pay on dates, whether or not you think it ought to be that way. It matters because whether you like it or not, you won’t be able to actually find a chick who will accept your cheapness.