I definitely see your point, but a piece of headwear can only be so bad or so good. Yes, skill makes a difference, but I have seen helmets made on the computer, and truthfully, they never look amazing. And it would be a clear win for anyone using zbrush, I think.
It isn't all that difficult either, to model a helmet; I think an environment isn't too hard for beginners to take a stab at, nor is it too easy for experts. It can also be made to look fantastic. Or at least a portion of the environment; some major prop in a scene. Environmental challenges are rare here.

Regardless, whatever the next challenge, I will participate.
Can't wait!