Rather than ranting about how 7zip interface sucks,
somebody opens a a call for "7zip" suggestions.
A place to upload existing screenshots, or use some
cool templates (full screen, small themed user
interface, etc)
Of course you could write text only, as well.
In any case, users vote.
If the company takes someone's design, people could
offer to be hired for graphics, or, just as important
could donate graphics for open source projects with
terrible UI.