This is the only forum I've ever really participated in, and I used to make a lot more comments, but a year or two ago I decided that no one really thought about other peoples opinions anyway, so why bother?
My breaking point was a thread asking questions about picture framing. This has been my profession for 25 years, and I really know what I'm doing. But people who don't do this for a living wanted to argue about it. I cannot understand why. And I suddenly couldn't understand why I was wasting my time pissing into the wind.
I think people start threads looking to bolster their own opinions, usually not to have them changed.