Regarding catching up you are right. It is always difficult, if not impossible to catch up with proprietary systems. I always wondered why the OSS community followed that way for so long instead of focusing on things which the user really needs and wants. Both Gnome and KDE for instance made the big mistake to ditch their very successful previous versions in favor of something many users didn't like.

Fortunately, and that's a big point for Linux, the user decides the further direction. KDE has become very usable again, and Gnome is on the way. In the Windows and Mac ecosystems the users have no choice.

Regarding Limux, I followed the Limux project pretty closely. I think this project failed only for political reasons. This conjecture is supported by the fact that most reports about Limux in Germany published only opinions of technically clueless political leaders while the opinions of the actual users were barely mentioned, if mentioned at all.

The point is, Limux had to fail by any means since MS could never afford a Limux success. If Limux would have been successful (and it actually looked promising) it would have been an example to follow for the whole world -- just for reason of license costs and source control.