I'm Ok for the early turn.
But in my own experience as a private pilot and controller, I can tell you that with the type of plane I'm used to fly ( 4 seater with 180 hp or even less) it's not really possible.
I'm not supposed to turn below 500 feet which means that I'm not able to do it before the end of the runway ( approx 9000 feet long in my home airport) ... difficult to avoid the wake vorteces in such a case !
Maybe we're just being too cautious, and I guess if you keep on using this method in the states it's because you've never had any accident, which tends to prove that you're right.
Anyway, just please don't be to harsh on a pilot if he's asking for these two minutes or even three, especially if he's not american. For in Europe, the controller has to provide the turbulence separation for departing a/c meaning that the pilot doesn't need to ask for those minutes.
Cheers.