what Nathan says about jamming the throttle.... plus.............

The idea to get the takeoff over with as fast as possible to avoid problems has killed more models than just about everything else combined.

The propeller is "flying" way before the airplane flies. Very often, nothing on the airplane is flying yet when the "slam and pray" flyer pegs the stick. It takes airspeed for the rudder to have authority. The elevator has little effect at low speed and won't have full effect until the airspeed has come up. It takes almost no time for the engine to go to full power and the prop to have MAJOR effect. The airframe won't have full "power" until it's up to speed. And "slam and pray" and there is a good chance that won't happen before it's stuck into the ground.

Your engine and prop takes a second or two to be at full throttle. The airplane won't even be flying yet. The wing will be starting to lift some, which will lift the airplane off it's wheels. And the roll stability they could provide will be take away from you right then. The rudder probably isn't working yet, but the tail wheel or nose wheel won't be either. And the elevator/stab might have some prop blast that'll get them working better in a few seconds. Until the airplane starts flying, the engine kills the model without anything to stop it.