Making Bumblebee voiceless was perhaps the wisest move Michael Bay could have made in his epic, rambling Hasbro-adapting franchise. The movies themselves are silly and the human characters in them are all clowns or eye-candy but the audience never seems to mind; they just want to see ROBOTS SMASH! The problem is, even giant transforming war-machines can start to get boring when theyre just racial caricatures, product-placements, or otherwise poorly written junkyard junk (and thats not even mentioning the inexplicable Fallen ghost-bots from movie #2). Thats where Bumblebee comes in. Leading man Shia Labeouf has a penchant for bad luck, and even though he spends the majority of the trilogy running around screaming no no no no the audience still wants to see him get the MacGuffin and the girl. Bumblebee helps him do that at every turn- taking bullets for him, turning into a sweet ride whenever Megan Fox (or whomever) is nearby, etc. The voiceless-ness only helps sell the loyalty, transforming Bumblebee into more of a ridiculously capable metal pet than a self-aware being, which Optimus and a few of the others at least seem to be. Who doesnt want a car that will also get you laid and save your life?