When you invite people to your home your expect them to be polite. Why should it be any different on an internet social site?

I didn't think there was a difference until you showed me that it's OK to invite someone to answer a question and then ignore the answer. Do you invited guests to your home and then ignore them? Now my guests may not always agree with me and they may even respond to me in a way that is less than graceful, but as they are my guest, I do not call them out their behavior unless it is affecting my other guests.