See, the problem is that he's using the name Transformers for all of his movies. If this was a stand alone project about robots who turn into vehicles and house appliances and go out and fight aliens and save the world at the end of the day, then sure, it would be a good movie. Not awesome, just good. But because he's using the Transformers shield, people can't help but draw comparison between the original story/sage/characters/whatever and...THIS.
Here's an example: Anyone like FF? Anyone watched The Spirits Within? Yeah, the movie was okay. But for FF fans, they were expecting Chocobos and magic and swords and spikey-haired people and fights and stuff like that. Instead we got...none of those. So the movie flopped. But the movie is alright if you try not to take it as a FF-based movie.
Personally, I'll admit they're fun. Not awesome, just...fun. But I'll also gotta say enough is enough. One movie was fine. The second one...ugh, alright. Third one? Alright, getting better, but just stop that right now. Fourth?! Come on, do we NEED another one? At this point, they're just messy and dumb and have lost track of the original story (I know it's not like it ever had a good track on it) and even the main human characters are gone. So what now? More buttrape?
I gotta give Shia kudos for leaving, though. He did what Michael should have done after the first movie. So props, sir. You've gained some respect points from me. Now you need 99 more points to go back to neutral.