You get back at them the most when you calmly put them down,whenever you let yourself be upset you just become their puppet to trigger whenever they want.
That said,i understand some situations are different yes but overall you can still try to be nice in general.
But they can take your calmly putting them down as weakness and mark as you as easy prey, someone they know they can harass without consequence, I've experienced this firsthand.
I don't believe you should be nice to assholes, that will only reinforce their behavior and may even cause things to escalate, but that's just my opinion. If your way has worked for you then by all means keep at it!