The Unix culture intrinsically values having so many choices, which is a consequence, I think, of historically being a platform by programmers/for programmers. Some people are picky about tools, and it encourages them to make their own. It's highly unlikely that it will unify in any real sense as long as its core design attracts people who bristle at the thought of being stuck using anything besides KDE, or GNOME, or Fluxbox, or ratpoison, or dwm, ...
I think it's a really good thing that different distributions tend to focus on particular goals, e.g. security as a design principle in OpenBSD, portability in NetBSD, being available as a free OS (in various senses) with Debian and Ubuntu, etc. (I really don't want this to turn into an argument about different distros; I know I'm trailing off there, I had a harder time summarizing Debian). Anyway, different foci lead to different discoveries, bugfixes, etc., but due to the pervasive Unix culture they are shared.
Still, that avalanche of necessary choices will probably keep it thriving in different niches from a system designed to have a consistent face for everyone. It's harder to teach people to use, harder to market, etc.
I think it's a really good thing that different distributions tend to focus on particular goals, e.g. security as a design principle in OpenBSD, portability in NetBSD, being available as a free OS (in various senses) with Debian and Ubuntu, etc. (I really don't want this to turn into an argument about different distros; I know I'm trailing off there, I had a harder time summarizing Debian). Anyway, different foci lead to different discoveries, bugfixes, etc., but due to the pervasive Unix culture they are shared.
Still, that avalanche of necessary choices will probably keep it thriving in different niches from a system designed to have a consistent face for everyone. It's harder to teach people to use, harder to market, etc.