I also notice that many people I've talked to over the years about this topic have a different idea of what sarcasm is. I think some folks just consider it humor and don't see it as negative.
Here's the Webster definition:
1 : a sharp and often satirical or ironic utterance designed to cut or give pain <tired of continual sarcasms>
2 a : a mode of satirical wit depending for its effect on bitter, caustic, and often ironic language that is usually directed against an individual b : the use or language of sarcasm <this is no time to indulge in sarcasm>
That was also how I perceived it growing up...a verbal jab, veiled as "teasing". In my mind, teasing implies that it's fun for everyone.
It can be a bad habit if one isn't mindful of this...and like I said, I'm still working on this one myself
