The "moralism" in Transformers is metaphorically cartoonish, the Decepticons are unfathomably malevolent while the Autobots led by Optimus Prime are motivated by an ethical compass which is broadly reflective of the "best in our natures." The saintliness of the Autobots has practical consequences insofar as it handicaps them in making Machiavellian choices to arrive at victory. The Autobots must sacrifice to defeat their enemies. The Deceptions have at their disposal the full sample space of options; by any means necessary is their motto, though their aims are often as inscrutable as those of the Autobots are clear.
I don't think this is quite right. The moralism in Transformers has almost always been primarily political, which is why (for instance) uneasy alliances between Autobots and Decepticons have been fairly common, something that can't occur in a genuine black-and-white morality war. It's also not particularly right to put sacrifice on the side of the Autobots alone; after all, the Decepticons have sacrificed as much in the war as the Autobots have. While Megatron has usually been protrayed as keeping his aims to himself, he has also been fairly consistently portrayed as aiming at the glory of Cybertron and its civilization. He just thinks that this aim can only properly be fulfilled by his leadership. And this is where the fundamental difference between Optimus Prime and Megatron arises: Optimus Prime, as the good domestic leader he is, defers private good to the good of the whole, whereas Megatron, the usurping military mastermind, recognizes no good of the whole inconsistent with his private good. Thus Optimus sets the tone for a very particular form of political self-sacrifice that Megatron does not, and the difference in the leaders carries over to the groups they lead. The Decepticons are not incarnations of evil; they are usurpers and traitors, willing to trample on rights in order to get the consequences they deem fit. The Autobots are not saintly (they are often, in fact, rather foolish and sometimes petty); they are patriots and defenders of the rule of law. And their interactions with us are extensions of this: the Decepticons come as usurpers, the Autobots as defenders of our autonomy.
* "Sci Fi Catholic" has a very critical review of the Transformers movie:
I have a lot of things to say about the movie, but through it all, keep in mind that the film's real, ultimate message is that you need a 2008 Chevy Camaro so that hot girl will make out with you on the hood.
Sounds reasonable enough to me; where I'm from it would just be considered bad manners to make out with a hot girl on the hood of a Camaro that's not yours....
In any case, it's interesting that the thing objected to most is Steven Spielberg's premise for the movie, since it seems to have been Spielberg who pushed for the teenage-boy-and-his-car theme (Michael Bay was originally looking to do a family film).
* "SF Gospel" also has a critical comment, but goes on to discuss Philip K. Dick.
* "The Knight Shift" has a very positive review.
* One thing you may not know about the movie is that there was a contest in which people could submit possible lines of dialogue for Optimus Prime; one line was chosen from these submissions ("Freedom is the right of all sentient beings.")