I belong to other forums, but none are as bad as MN for posters not reading the thread. I know that some threads can be very long, but at least scroll through quickly and check for updates from the OP. It's easy enough when they're all colour highlighted.
And what's with people who come on and say "I haven't read the thread but...(insert stupid question that's been answered ten times, or a point that's been made 100 times)"
Do people actually want to look stupid? I don't get it.
Oh, and when the OP has already realised they're being unreasonable (five pages back) and accepted every point graciously, you look a complete bitch when you rant at them for being a terrible person.