I might need to clarify that the Iron Giant is also a good movie. It's also got its own elements to set it apart from that movie. Cybertron, Charlie's backstory with her father, etc.
And Soundwave, and Optimus Prime, and Ironhide, and the seekers, and... I don't really see your point here. The trailers showed plenty.
They also weren't showing the usual bayformers nonsense, which was more than enough to put me in the theatre. It looked like it would actually have some kind of heart to it, unlike this.
I also object to this ridiculous notion that kid's movies get a free pass to be lazy piles of garbage because they're for children. Some of my favourite films are kid's movies: How To Train Your Dragon, Treasure Planet, the Lego Movie, Kung Fu Panda 2. Just because they're for children, that doesn't somehow bar them from having beautiful scores (okay, maybe not the Lego Movie, but everything is awesome still fricken bops), breathtaking visuals and compelling characters.
Kid's movies have moved me with the unbridled freedom of flight, and adventure, and brought me to tears over a gosh darned panda. So excuse me, if I object to a whole swathe of films being dumped under that one banner.
If you just want dumb fun in any genre, that's perfectly fine. I like some dumb fun every now and then, I just object to that particular defence on a conceptual level