If this is the attitude of all community developers then free software UI will never become successful.
And that said, it doesn't need to be so difficult to include all these pesky checkboxes in a way that they don't confuse or hinder usability for n00bish users. This used to work for Gnome 2. Never met anyone who thought Gnome 2 was too hard or counter-intuitive, they were just more or less used to it. Windows XP and Windows 7 have a lot more checkboxes if you look for them.
If there's one thing that Apple and even Microsoft are showing with their window manager and widgets, its that simpler is better, and we've been missing that all these years.
Whether you call Gnome 2 hard or easy, it's main problem was that it's configuration apps and menus were confusingly organized. If the incremental improvements Ubuntu was making could have continued a few more years, things might have been great. The decision to create "Gnome shell" probably forced Canonical's hand but Unity also seems terrible to me.
I like solving problems for other people. But when I'm using open-source software, the only problems I'm really aware of are the ones I'm having.
In a commercial setting, I'm very motivated by user tests or data that demonstrates problems people are having. I've seen a lot of other developers get excited about that, too. Fixing things is fun when you can see that your actions actually help somebody.
But I've never seen an open-source project that makes it easy to get engaged in that fashion. The closest I've seen is users asking support questions on the mailing lists, which is a pretty small slice of users these days. Plugins also seem to provide a nice feedback loop like that: you make something for yourself, you throw it out there, and you see people installing it and commenting.
But broadly it seems like an unsolved problem in consumer-facing open source.