Why GNOME refugees love Xfce (Register)

Choosing to use conflicting names for all the binaries and the same namespaces for the settings means that the only way to have GNOME 2 and GNOME 3 on the same machine is installing one of the two on a non-standard path and doing a lot of clever things with the environment to ensure that what needs GNOME 2 can find it and what needs GNOME 3 can find it, or patching all the GNOME 2 packages to append "2" everywhere (or switch to a different name like MATE did) and altering all the software who depends on GNOME 2 to cope with the unexpected "2" or the new name.

Now it is true that they didn't resort to physical violence or legal threats, but for me what they did is enough to say that they made parallel installation impossible for all practical purposes.