[ductsurprise]

There is no reason they cannot be installed beside each other.

GDM, etc have made this easy for years. On installation 'simpler' distros let you choose as many desktop environments as you wanted from the install. (Gnome/KDE/XFCE/Flux/...)

And you still had /home/[user] common between desktop environments by default.

If someone has been using Linux since 1996 and is surprised by this "rebase"...

Benefit of doubt, maybe a poorly chosen analogy?

Edit: also, with no malice. that justification sounds like rebuilding the wheel. Package management system == Wheel ...