I think this is a great point, and helps explain why much FOSS software is clunkier than its commercial counterpart.
Although I don't think this is an issue of good, professional developers vs bad, amateur ones. Sometimes the same developer works on commercial and FOSS projects. It's just about the nature of work.
Work is hard. That's why you have to be paid to do it. If you're doing a project for fun, you'll probably stop when it stops being fun.
For many of us developers, the "first 90%" is fun and intrinsically motivating; the "last 90%" sucks and we do it because it's what we're paid to do.
Although I don't think this is an issue of good, professional developers vs bad, amateur ones. Sometimes the same developer works on commercial and FOSS projects. It's just about the nature of work.
Work is hard. That's why you have to be paid to do it. If you're doing a project for fun, you'll probably stop when it stops being fun.
For many of us developers, the "first 90%" is fun and intrinsically motivating; the "last 90%" sucks and we do it because it's what we're paid to do.