Probably the biggest reason for all the crappiness in Linux GUI applications is the lack of a testing paradigm with most languages used for the purpose. The notable exception is Java, but that still has no GUI testing framework in its dev kit. At the time people hear about something like FEST they have switched to another profession.
Recently I commented about a bug and got from the dev the answer "The tracker can be accessed here." but I had given him a link of a distro tracker issue before which he simply ignored. No wonder his application was crappy if he did everything to sweep bugs under the rug. As a dev, I'm willing to go miles to have a full tracker regardless of how a many issues are open, because I *know there must be hundreds of bugs, I just haven't found them.