I don't think offensive means quite what you think it is...being corrected on something is not offensive, and being informed that you're not being helpful when you aren't is also not something you should be taking offense to. Now, I have no idea whether or not you are correct, but I see two options here.I was being helpful and for you to say I'm not being helpful is quite offensive.
1: You think you are correct and helpful. In that case, you can explain how and figure out why people are disagreeing with you.
2: You realize that you're incorrect, or the other person has more knowledge. In which case you either can leave it alone and let them explain, or ask questions to understand more.
I can't think of a third way where the appropriate response would be to inform the person they are being offensive, and leaving.
Unless, someone actively stated you are a bad person in some way, or you do not belong here (no one said either of those), in which case that response would make more sense. If I somehow missed where they were being actively offensive please enlighten me.