Koos Looijesteijn: Why is open source software so badly designed?

Great design isn’t done by picking up a tiny issue and creating a solution for it. It’s done by gaining deep understanding for the problems people have, the context in which they use products and by testing solutions with people. It’s labor-intensive and requires people who are engaged with their users over long periods of time.

A very good read about the structural reasons open source software often has less-than-wonderful UIs.