That is my biggest pet peeve with most F/OSS software. The software works as a free alternative, but since it is free, it is often left in the "Good enough" state. Often times, when someone complains about a F/OSS product, one of three responses comes about:
A. If you don't like it, don't use it. It is free after all
B. You can't complain about something that is free.
C. Take the source code and write your own.
In most projects like this, everyone wants to do the sexy pieces of the project that everyone sees. No one wants to take the time to make the UI fluid, eliminate graphical glitches (Yes, they matter to the average user and indicate a level of quality in the product), or to perform proper logic within the application.
This is what turns me off to most graphical based (which is what the average user will want) programs in the F/OSS world. I can't tell you the number of times I watch programs create artifacts or react unpredictably each time I use Linux (And yes, I use it daily. Namely, #!, Fedora, and Suse (Backtrack if you count work)). Predictability is huge and is definitely a piece that Windows/MAC have a leg up on when compared to Linux.
Is there going to be a "Time for Linux"? Probably. Is it any time soon? Not until applications and windowing/UI systems mature.