be the change you want to happen

I see this thread a lot too (and agree with the quote I put here), and I maintain that if you want change, you must be the change you want to happen.

If you want people to be patient with you, be patient with them.
If you want people to be courteous to you, be courteous to them.
If you want people to be helpful, be helpful yourself.
Even when you want something for yourself, be generous to others,(more often than not) they'll be generous in return. And if they aren't, don't sweat it.
www.euwowgold.com
You can choose to let the rude people get to you, or you can move on.

Here's a mostly opposite experience that I had from what others tend to report. (Yes, I am completely anonymous in game.)

The other day, I ran some dungeons (albeit normal ones) with a random group. At first we had a mage who didn't know what they were doing. The mage eventually left the group. No one yelled at them other than asking them if they knew what they needed to do. While people griped about them to the group, I mentioned that perhaps they were new or young and didn't know what they were doing.