I am well aware of all of those, and they fit into be "with" category above. All of those are VERY large scale projects that receives major backing corporate and non-corporate alike.
Unfortunately most linux programs do not receive this major backing, and do not have the luxury of large teams of developers as these projects do. Thus what you are left with in the end often consists of programs that work. Not much time is taken to truely refine the interface and install to top notch standards, let alone so quickly as these projects have attained it. Another thing about all the projects listed above, how old are they? You answer is quite old
Open source has yeiled a great many wonderful programs that rival the best software ever written. However most consumer apps written by small teams, that are not that old do not by any means rival it at all. Myth and Freevo are quite the exception in this case and show great matuity for their age.
Jkrohn