The problem isn't that they're not-G1 enough, or not striving for some exceptional artistic recognition. it's that they're stupidly scripted, racist/sexist and downright bad. Sure, you can have giant alien robots fighting over mountain dew/xbox/whatever. Sure, go spend $150-300 mil doing CGI/good VFX. But for god's sake, don't make a film based on a first draft done by a scab and a 45-50 year old frat boy. The problem there is that since ROTF came off the success of a not too bad film (TF1), it was going to pretty much guaranteed to be a success anyway (powers that be, all that). Which means that since then it's actually potentially made other films dumber. I dunno.
(That being said, enjoy what you likeIt's just I know big budgeted action films have and can be both trashy, enjoyable AND not downright insulting, and we all know that Transformers can be better than other people expect/anticipate. So it'd just be nice to see the flagship of the franchise/whatever be something that isn't just dumb as heck (despite it's premise (bracket (small joke))))