Not because it's "stealing" from KENTA or whatever, but because it looks pretty horrible when he does it. I've yet to see a good looking version of the move.
Kinda thought Punk would be able to do it better, but I dunno. An urinagi into Anaconda Vice looks much better than Punk's G2S.\
http://www.wwe.com/shows/ecw/shows1/...ideos/4524564/
(Watch the 8 man tag match)
By the way, that's how he should have turned heel in the first place. Mosy on up to RVD or someone and kick him in the neck. Then hit his finisher.