I agree he hasn't been the same fighter since the first Serra match, but Georges shouldn't feel the need to try & justify his wins. 14 of his 22 wins have been by submission or stoppage, and his decisions have been mostly very dominant...no other fighter with a similar record gets raked over the coals like he does. FWIW, I've seen fights get stopped for less than the beat downs he gave to Kos & Fitch too.
It's obvious to me that his ground & pound sucks, relative to his other skills. Stand up is technically very solid, and of course the takedowns are great, but he isn't going to pound anybody out, so he might as well let 'em stand a minute after getting the takedown and continue picking them apart on the feet.