It's silly-looking in a vacuum, but you could say the same about anything in Halo 1. The important part is whether it works in the context of Halo 1, which it does.
I guess... but it is about the only thing in CE that i do find silly. In retrospect.
And disregarding obvious idiocy of some design, such as the Warthog (no seat belts, flips over easily, as far as military vehicles go it is completly insane). But the 'Hog looks damn cool. The marine armor is just... silly.