Of course GNOME fanboys complained that someone dared to replace their precious DE with a nicer Qt based one instead of kissing the ass of giant ego GNOME designers. Even when Ubuntu got back to GNOME Canonical listen to the users and put features back in on Ubuntu.
..wonder what I'll do after the Gnome team kills XFCE by enforcing Wayland for GTK.
You can't please everybody, but both Unity an GNOME shell had some very bad ideas, and it took too long to correct course (and in some cases it didn't happen). I believe some of the criticism came from people that really loved those DE, and that's why they were passionate about it.
When people don't care, they just use something else.
There were a lot of hather, sure there were some valid criticism but you can't invalidate the fact they were haters, and if we would want to waste our time we could read those old topics and find them but we have better things to do.
IIRC I used Mate as a temporary solution, and happily jumped to Cinnamon when it came out.
Nowadays I use Pop Shell because (at least when I switched) it seemed to offer better widgets for controlling audio, etc. on my System76 machine.
But we KDE users should we hate Canonical that they were pushing GNOME? I did not hated them for this though I am puzzled why not create Unity based on KDE libraries (probably there were many reasons some including Qt and C++ are ugly)