I stil don't know why you have to push the brakes more. AHA! I figured it out. You drive an automatic. You don't need to worry about the clutch then, duh!!! cause you don't have one. I don't know if that will do any damage on an automatic transmission, but here is why the clutch would wear faster:
The clutch engages with the flywheel. The flywheel spins with your crank. The higher the rpms the faster the crank turns, which means the flywheel turns faster. When you normally take off, 2000rpms is plenty to get you moving. So you could take off without pushing the gas. If you do puch the gas, you will be at what 2300-2500. Well, your clutch will slip just a little bit(not even noticable), but the more you do it, the more the clutch will slip/wear because the flywheel is spinning faster.