Sure, it takes work and testing to get a UI into a condition that seems, to the end-user, to just work
BUT that kind of work, each in the small end-cases that only come up ocassionally, is needed. Sure "that doesn't affect a lot of users...".. yeah it will continue to "not effect a lot of users"* as long your usability sucks and not one uses the thing...
An app or desktop or whatever needs to fully implement the features it claims to have. And it is often true that the last yard turns out to cost as much as the rest put together. Yes but the last yard is necessary. I can understand if it won't get done 'cause there's not enough time or money. But the attitude that it shouldn't get done 'cause "that doesn't affect a lot of users" makes my blood boil. Sorry, I'm sure people put lots of effort into this stuff but I just have to get this off my chest.