Personaly, I think controalability is all in the user.
I can control and have had occosion to fire some heavy weapons that were fully automatic: An MP5/10, a HK G3, and even a GLOCK 18. (One of those places were you pay a rent on the gun and ammo and they let you have fun).
Now, if you were to hold the trigger untill the weapon went 'click', controalability would be insane, even for a big guy like me. But short bursts and taps aernt that bad...
As for needing one, I dont see why Joe Smith would, but its his right to own one, and he can if he so wishes, and has the money, of course...
I may only be 16, but I happen to know what I'm doing. Now were is the safety on this thing?