One of the best things of FLOSS, is the fact that the end user is free to choose the desktop that fits his needs and works around they way he does things.
This is an important aspect for me, because it means that the desktop environment becomes almost invisible letting the user to focus on the work at hand. But, this is something really hard to implement.
Almost any detail can derail the project, since the each user has somewhat different perception. Which means that some users will notice things that other user won't. What makes the desktop a joy to use and work with, can ruin the whole experience to another.
So, for the whole argument that Linux is becoming to fragmented desktop wise is something of an annoyance. Yes, there are several options out there to choose from and users are adopting them because they like the way they work. That users have options is a good thing, and they should also have a say on which desktops environments there should be. Not only that, the users should have an influence on how many of them should exit.
We are entitled to use the desktop we like the most, but we shouldn't be belittling others who use different desktop just because we don't like what they use. We could see what they are doing right, and port those features on our desktop if we find them useful.
The world is a big place, and we all can share it peacefully.