KDE used to be the "bloated" desktop way back when (I know, pretty silly and laughable now given the current state of things).
That cemented Gnome/Mate into a lot of major distros as the primary DME. Ubuntu being the most famous.
The QT licensing situation is also a bit of a bizarre quagmire. There are certainly people that don't like KDE for more ideological reasons.
Personally, none of this bothers me and it's what I use for my personal computer. KDE is just so close to exactly how I'm used to interacting with computers anyways growing up through the Win95 era. It is so close to the Windows experience you want to have.