99% of the time, if a file just loads up and plays in popcorn time, then you won't have to seed very long to get a perfectly good ratio. It would be nice to seed long-term, but a positive ratio is enough to not cause any harm.

I understand how tragedy of the commons works just fine. I just don't understand why culture matters if you're not talking to someone and they're not breaking anything. And they're not going to be on a private tracker.

It's true that I've never been on a reputable private tracker, but every time I've looked at one it had an obnoxious process to join that has nothing to do with my ability to seed lots of bits for a long time.