Jedi don't use the force to attack.
And they are still spending years and years mastering all these techniques.
Jedi are a contradiction anyway. They are passive and hippyish but they all carry the most lethal weapon around. You can understand that it's for defense but they don't need all these superpowers as well.
I have a problem with the jedi only use their powers for defense, not attack, at the end of tpm it looked like ob1 and qgj were doing all the attacking while Maul was doing all the defending, in esb, Luke strikes Vader first I think and Luke tries to strike down the emperoer in rotj, perhaps its the Sith who use the force as defense, they're the ones always being attacked.
It seems to me to be a case of the best form of defense is to attack!