I have heard that in some cultures, they don’t flush the toilet for 2 kind of different reasons. One being that toilets in some other countries don’t have a flush mechanism at all, so those folks are probably unfamiliar with U.S. toilets and customs. The other example is that in some countries, there are actually people/attendants who have the awful job of flushing the toilets (and usually the pooper puts the toilet paper into the trash can instead of the toilet, which is also kind of gross, but they do that because the toilets in those countries can’t accept toilet paper, it will clog)
As for home use, when it’s just immediate family we go by the if it’s yellow, let it mellow, if it’s brown flush it down. But we always flush if we have company!!!