Which doesn't mean I'm wrong and you're right. It's just two different ways of doing the same thing.

On big food courts here the etiquette is to return the tray to the tray holders or to the store, but for small courts or restaurants it's very common to leave it at the table for the employees to gather. So it is kind of inverse of the cart etiquette. In some places in the world it is common to return the tray, and in some places it is common to leave it at the table. That doesn't mean either is wrong.

The world is big and different people have different views and cultures and ways of doing every single thing. To tell one is superior to the other when talking about these things that don't matter so much is to impose you way above anyone else's to feel superior.

The person that called me lazy was calling everybody where I live lazy because everyone does this thing this way, which is pretty pretentious.

You can have strong opinions about something without being judgmental about how other people live because they don't do things the way you and your peers do.