I did exactly that: I use KDE.

There are plenty of OSS projects that aren’t DEs.

Then maybe some of those project maintainers should start a DE, and see first-hand how it's really difficult and requires making a lot of tough decisions that don't apply to other projects?

Funny how the KDE guys never seem to get quite this level of flammage.

I extensively use Gnome but I think it might be time for me to consider switching.