Is the nostalgia factor stronger than bad acting? First thing that hit me, and it hit me hard, was the design of the Transformers. It was so true to their original cartoon/toy design that it struck a deep chord in me. Being able to recognize my childhood favorites (Soundwave, Cliffjumper, Optimus and the rest) really jump started my nostalgia sensitivities. Further on many popular 80s hits (as the movie is set in 1987) kept coming up which added to that, but that was only distracting enough to make a mediocre movie enjoyable.
I'll leave it to Youtube essay fanatics to nitpick at every excruciating detail, I'll use broader strokes today.
The coherence of the story is wildly inconsistent. A product of bad writing of course, but again, wildly inconsistent. Some parts seem well thought through, well written and constructed while others are severely cringe-inducing in their juvenile nature - especially the bonding scenes between Charlie and Bumblebee. In their scenes he's reduced from a heroic soldier (as seen in the beginning) to an idiotic, pathetic puppy like creature. Kind of like a huge, metal Gollum. Their scenes together felt weird and the base of their bond was inappropriately based on her personal loss, rather than experiencing something together. That direction forced a lot of dry exposition that completely detached from the rhythm of the movie. It kept going when the character of Memo was introduced. It became a full blown straight to DVD Disney special. A true cringe fest, and that's without even mentioning the "humor". How bad could it be, you ask? There's a scene where Bumblebee is TPing a tree and throwing eggs. During those scenes they completely lost me, and they kept going for a long while. A very... long... looooooong while.
The music... *sigh* The use of pop songs was great, you can't go wrong with 80s music. However the soundtrack was awful. Most of it sounded like stock music that was downloaded for free. Cue "dramatic-tension-38.mp3", and now "comedy-20.mp3". This may be a small gripe to most, but it's a powerful mood setting tool most people are unaware of how much by which they're affected.
Overall I enjoyed the movie, in spite of the difficult-to-watch the Disney moments. It felt like it was made by people who liked the Transformers as kids as well. As if they got the spirit of the original show, unlike Michael Bay who seemed to have hated the original show and tried to tarnish it as much as possible.