Exactly. Ubuntu started out to be the mainstream distro that just makes the linux desktop experience smooth and free of worries, but instead they now build just another desktop experience on their own.
Even for Ubuntu you have Ubuntu, Kubuntu, Xubuntu, Mint and-i-dont-know-what else...thats just the wrong approach imo.
That's because people don't figure out that every Linux can run every WM or desktop environment anyway. So they need a seperate distribution just to switch from Unity to KDE...