You want respect as a GM? Earn it by setting reasonable limits... then stick to your guns. GMs who sacrifice fun, challenging sessions by courting player approval run the risk of ruining their game.
You've heard of passive-aggressive? I'm talking about whiny-aggressive! Don't let bastard players walk all over you. Respect your game if you want others to do likewise.
Of course, there's always the third side - let them make whatever characters they want and then shit all over their uber-optimized, bitch every time they break a nail Masters of the universe. Will they learn from the experience? Nah. But it's quite therapeutic.
Alright, back to the stables, pig-fucker. We're done here.