I hope that this comes off as encouraging more than discouraging, but this lack of design and accessibility comes from the fact that it's all volunteer work, and volunteers are going to prioritize what they need. The big companies don't have smarter people working for them. They have money to spend on full-time developers (and designers, and writers, and...you get the idea) and someone at the top who wants to turn that investment into significantly more money by selling the software to people.

That's a huge problem, because it puts up a wall between the people who do the work and people who just want to use the results of the work as the workers offered. And I don't know how to fix that, other than to start making a bigger deal about the cultural aspects of Free Software. Like, a particular user may not care about how programmers develop the software, but by showing up and getting to know people, their one-off bug reports become something that people take seriously, because they know that person.

...But that obviously drifts further off topic.