People are sarcastic in real life too. “Want a medal?” is usually harmless.
The main lesson here, as always, is don't tweet... it's a context-less shitshow.
Speak however you want, but as always people can label you a jerk for anything you want no matter how little offense you intended by it. It's a design flaw in language that's impossible to eliminate.
And in the second case, it's more of a feeling of disappointment. "I know you're better than this, why are you wasting your time being mean to strangers on the internet?" But I can't quite put myself into the mood of getting angry at them and trying to bully them into deleting their account or even getting them fired from a job. I'm trying to understand that.