This is a joke, right? You're doing some-kind-of impression of a radical fanboy picking out petty flaws? I mean you came "this" close to complaining about the color of his nacelles.
To me he looks like an intimidating man surrounded by the treasures/tokens for those he's slaughtered. The camo pants? Eh, it's just an image thing. Again, probably a "trophy" from some conquest or maybe nothing else fits. I doubt he gets to the mall often to buy a good, real, set of pants.
Man, to write the whole movie off just because of how the villain looks in a promotional poster? Pretty darn lame.
It's just another nitpick in a long line of nitpicks.
-NO RED TRUNKS?!? This movie will fail"
-Flames on Optimus Prime
-Blonde James Bond
-"teh puffy" batman begins suit
-Fruit rollup Superman cape and muted colors from "Superman Returns
-Bobblehead Batman in "The dark knight rises"
-No zero on the Enterprise
-The entire 2009 Enterprise
And others i'm forgetting or choosing to forget or just don't care to remember