Ok, this is probably just me, but there is something way cool about seeing a ninja rise up 30 feet in the air from a standing position. Check this out:
Yeah. Newton's third law states "For every action, there is an equal and opposite reaction", so, if you estimate that this ninja weighs 80 kilograms (~160 pounds), and the force of gravity is, what, 9.8 meters per second square, the force for takeoff comes out to approximately 800 Newtons (assuming he takes one second to lift off) which is, um, pretty high.
Given the number of times people do this in Naruto (these screen caps were from Naruto 65), it's a wonder that you don't see impact craters from ninja takeoff locations ()