[dispose13432]

>But 10 different desktop environments are each solving the same problem 10 different ways, consuming 10 developers time, when a collaborative project would be able to reduce that by a huge factor and benefit everyone.

Most of the time, they don't merge because they don't want to.

For example, the guys working on Gnome3 wouldn't want to work on LXDE and vice versa. People want to scratch their itch. If I have a light computer (or have heavy tasks), I cannot run Gnome3. If LXDE didn't exist, I would go without a window-manager or would switch back to Windows.

And many who would look at an "ugly" DE like LXDE would switch back to Windows if they didn't have Gnome3.