GNOME development has been mostly design driven since maybe 2008, the whole 3 era had professional designers on board since the beginning.
I know, and how much FOSS bashing have they received for their ideas?
Definitely too much, mostly by a vocal minority of the userbase. I guess design is not enough, you need good charismatic leaders to be able to sell it to the community, and you need to be strong enough to not care about the criticism.
That said, not all design is made equal, sometimes a little dose of reality check from the community can be helpful.
They got bashed for removal of options (that could be hidden from average user), also they changed a lot of things and more or less reimplemented things that they didn't want to do at the beginning (and where bashed for lack of), so I'd say they made a lot of mistakes - for me gnome is usable without heavy tweaking since last year.
Which means it took 4 years to get it to usable state where i don't have to download tons of plugins to make it effective environment for work and multitasking.
This is why many of us that enjoy UI design ended up going to platforms where it is praised.