I try to take the same attitude as SheFly, although I am clearly not at her level! I ride with a couple of friends who are slower than me, because I want them to enjoy riding. I also enjoy having my DH or other males push me some of the time. I don't do most group rides because of the phenomena described, and I am lucky I found a group that has the same philosophy as me.
Now, I just need to get to the rides more this year.