In those cases I think it's the others not respecting someone else's opinion, something I really hate. I understand that things like religion and abortion can be delicate areas, but it's unfair to take the elitist stance and tear someone down when they're stating a valid opinion, that's just not right. Back when I was on GBAtemp, I would actively participate in such debates, by collecting information from the first post, posting, waiting for a rebuttal, and then using that rebuttal against the person who presented it (or at least I try to). It's not always the best idea as your counterarguments might not be too strong, but you should try it sometime, because I really don't like the idea of someone being alienated because people don't respect their opinions. Don't restrict yourself for the sake of others.