Everytime I get excited about the story for the movie, I just utter the name Ehren Kruger and immediately my expectations lower. The guy hasn't written a good movie yet(Arlington Road was decent).
I think his original script for dark of the moon was decent, the film itself just had production issues ( megan fox leaving three weeks before filming, Michael bay deciding for prime to kill megatron instead of accepting the truce etc.)
I was kinda iffy on that as well, but like the previous guy mentioned in both ROTF and DOTM production had issues, I felt like a lot of things were rushed/last minute.