I think that part of the ugliness comes from having so many contributors and a culture that is used to things not having a consistent look and feel. On OS X al

I think that part of the ugliness comes from having so many contributors and a culture that is used to things not having a consistent look and feel. On OS X almost all native programs look and feel the same way and the frameworks and tools encourage developers to follow Apple's human interface guidelines. When someone uses another toolkit, such as Qt, the apps just don't feel right. On Linux there is not single toolset and if there are human interface guidelines they don't seem to be followed. So the problem isn't that you need to change a few small things about some interfaces, it's that there needs to be a strongly consistent design that all programs follow.