Sarcasm is a great tool. But there are a couple of people I know who never turn off their "Sarcastic tone", and it becomes impossible to tell what's genuine and what's bullshit. I try to tell them that their noise-to-signal ratio is bad, but they um... react defensively.
The key thing about using sarcasm is that you should never direct it at someone you're talking to. Doing that is a great way to make someone instantly dislike you.
Sarcasm as a form of humor is too easy to do. You don't have to be clever. You just have to look down on someone/something and then caricature it. Whoever does that too much just seems unlikable.
When you're actually clever or subtle about it, people tend to enjoy the twist that makes the joke.
It can be a coping mechanism for depressive people just like cynism, at least I know that it serves that function for me: Can't be straight up negative, for dragging the mood down, so I'll settle for some sarcasm.
