i have a simple solution. GIVE EACH PLAYER THE CHOICE TO SHARE THERE DPS WITH GROUP OR NOT. have it as an option as soon as you join the group.
If they don't want to share there DPS, and you are dependent on every member of the party doing there maximum DPS, then you can boot them before you even get started.
If you feel sharing your DPS is not fair, for whatever reason, then you don't have to. Join a group that wont require you to share DPS.
And for the 95% of gamers who really could care less if a raid takes ten minutes longer than expected. We can all go about our business having fun playing the game on our own term. occasionally getting yelled at by elitists and occasionally helping out a noob who is struggling to get his class figured out.