It's interesting to me how different the opinions are of people who are interested in research and advancing technology vs. business people and consumers who, ultimately, are the ones using that technology.
I love seeing new progress but I have to admit that my job would be a lot easier if there was one operating system and one browser!
It's particularly interesting to people like me (and I suspect many others on HN), because we straddle the line ("wear many hats"). I personally love crazy ideas (everything is a file! No, really, look at Plan9!) and wild research directions. But for my day to day work, where I have to ship? Linux just works. But I also like having options, both to play with (personal) and to solve problems (work). In many respects, Linux already has enough flexibility and options to satisfy me.
As for fragmentation, get used to it; it's part of the job. Things are more unified now than they've ever been, it might not stay that way, and one of the major thrusts of the OP (and many comments here) is that there may be too much unification, and not enough variety and options.
I love seeing new progress but I have to admit that my job would be a lot easier if there was one operating system and one browser!