The Captain America does not look that bad to be fair, but its very much a "meh" effort from £avvi. They could have done so much better than the designs chosen.
I think it's been shown that Zavvi do listen. They ran a poll on the interior artwork for The Wicker Man, they've also changed the artwork for The Goonies.
The thing is, by-and-large, Zavvi don't really have a say in what artwork is chosen. They can ask for exclusive steelbooks but I suspect after that, it's pretty much out of their hands.
Paramount have (more often than not) simply reused existing artwork on their (re-release) steelbooks. The Untouchables, Iron Man, Iron Man 2, War of the Worlds, Mission: Impossible 1, 2 and 3 and so on and so on. I'd say that Zavvi have no say over what the product looks like or how many discs it contains etc.
If Warner wouldn't alter Batman Forever to match the other 3 (even though, they must have known people would complain, and had plenty of time to do so*), what's the chance of Paramount listening?
Artwork is commissioned, signed off, gets actor, director approval etc. etc. and that's what gets used. We just have to accept it and either buy, or not buy accordingly.
*ironically, they have changed The Goonies!