I think that once i get ubuntu installed, updated, and all set with the right programs, it is very stable and easy to use. I have done that for a few friends and they haven't really had big problems with it. For me, personally, the main reason ubuntu is difficult is when i want to run something designed for windows on linux. And i can't really blame the ubuntu developers for that. For example, there is no linux distro for itunes. That just seems crazy to me. Why does apple care if someone uses ubuntu, or windows to run their ipod? they aren't using apple hardware anyways.
Most users just want a nice OS with features designed to make their life easier on the computer. They want all those features out of the box and they don't want to tinker with their operating system. They want it to just work for them.
I think that the job for Ubuntu developers is much harder than for windows and Mac because they have to make ubuntu compatible to other systems, hopefully every system combination in the world. that is a hard job. Windows and mac developers know exactly what hardware they are running, and the hardware companies also work with windows to make it all compatible. It is a much bigger job for ubuntu. Given all of this i still think ubuntu works great for me.
At the very end you have to look at the ubuntu guarantee:
"Ubuntu is and always will be free of charge. You do not pay any licensing fees. You can download, use and share Ubuntu with your friends, family, school or business for absolutely nothing."
That is amazing to me, and i love that ubuntu already works so well, i hope that as time goes by we can all add to its completeness and usability.