The root of the problem is and always has been that players just don't stay in their lanes.

If mobs are dying fast enough that healers don't run out of MP - DPS is fine.
If no one is dying and staying out of telegraphs - Healing is fine.
If mobs are on the tank and not chasing people - Tanking is fine.
If the above are true - The group is fine, sit down and do your role.

The issue comes up when those things are happening and people are taking time away from their role to see what other's are doing and thinking they should do more. The ironic thing is, if you can tell your healer isn't doing damage. You're not doing damage either.

Or when you perceive someone doing something contrary to what you think they should be doing. If the above three things are fine, just keep on going.

I don't understand why people in a PUG can't simply do their role and shut the hell up. What you do or say in your guild groups or statics is your business, but leave it there. If it makes you all feel better, take the following as a threat: if I see people messing with healers that are doing fine, I will boot you. I've done it to two people already since I've come back to the game. I usually run with a tank friend so you are SCREWED if you tick me off.

Its easy not to tick me off though. If you're a DPS just DPS you'll likely even get a Comm if I don't have to fix too many of your mistakes. If my buddy decides to DPS and you're a tank, hold agro. I don't even care if you pull like a madman, just hold the threat and don't pull more than you can handle. But if you pipe up about something stupid, back to the queue for you. Its not even negotiable, debatable, or open for discussion. That's just how its going to be. Period.