Well... I don't know how much this guy knows about and understands what TF is... DOTM was a good movie but I think there's something else We can read in his words. He's shifting towards G1 design because the next movie will be more on the BBee style. It's not a mistake in itself: I like G1 design and I liked BBee very much. The mistake is saying that DOTM is a bad movie or that the Bay TFs design was ugly and not iconic: He should remember that in 2007 They had to REINVENT TFs because the were making a film not only for fans so They tried to reshape all the carachters. It was an option and They've done a good job in my opinion, even if at that time many fans were upset for the new design.
What I want to say is that G1 style (which I like more) and 2007 design are both good and are different ways of looking at TF franchise and different ideas about the movies. DOTM isn't a bad movie, moreover if You say that it was bad due to robots shape. The really bad movies in TF were ROTF and AoE, While TLK was nice but simply not a TF movie: it was a "something else movie" starring Transformers.
Anyway, I hope next movie will be more like BBee