No it doesn't. The spirit of the GPL is essentially "do whatever you want with this as long as you keep distributing the source code." That's it. It says nothing about paid products or development style or keeping a certain style or direction or anything like that. The GNOME developers decided to change direction themselves, as the GPL says anyone can. It would no sense for them to give up their trademark to MATE when that was just a random offshoot that no one had any idea of whether it was serious or how long it would last. It's not even that active now, can you honestly say they would have benefited any more from having the GNOME name?
Like, come on my guy, you're flogging a horse that died more than a decade ago. You can continue this substance-free criticism of open source projects for as long as you want, just be aware that you get out what you put in.
You seem to grossly misunderstand what "spirit" means here, because you described the letter.
>the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users
And that part's still the same. You can share and change it as you wish.
This ain't just hobby stuff anymore. Businesses are catching on and using it, and so they're entrenching an older, stinky, take-it-or-leave-it way to do software, and what's worse, they're doing it on the back of a free-software-spirited labor.
It doesn't violate the letter of the GPL, but it sure as hell violates the spirit.