The same principle applies.

The principle of not trying to offend because it's childish?

I don't like swearing, and I really try to not offend people. But telling someone not to do something with the sole reason giving it's childish I dislike strongly.

I sometimes play video games, even though some people say it's childish. Or act silly with my partner. What ever floats your goat.

The swearing is something that makes sense when it's a situation to swear. I would not trust person who never, under any circumstances swear.

The same thing would apply to a person who swears endlessly without reason.

>I sometimes play video games, even though some people say it's childish.

Who cares what you do in your own time?

Here, on the other hand, someone is trying to force his opinion on public. This, I can judge. Both on merit, and the language they use.