1Pe 3:15
But sanctify the Lord God in your hearts: and be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear:
We need to work on the meekness, no doubt about it
Courtesy and respect is necessary in public discourse, particularly about religion, and being a jerk is a non-denominational affliction.
I don't believe I've seen anyone who was making a real effort at basic respect and courtesy be asked to stop talking to someone. Some people enjoy a flame war, but some don't and some are more sensitive than others. I think you have to respect their requests.
And sometimes stopping the conversation is best for the posters and the forum as well.
I understand what you're saying. Still, I think it is biblical. I'm referring to Proverbs 26:4. Let's say somebody identifying as a Christian follows another Christian around on different threads, replies to posts but not the content of what was actually written, and then asks why their questions weren't answered? Repeat this over and over. Sometimes our time is better spent on more productive endeavors and asking people to stop responding to you is the last resort.