It doesn't make any sense to have in one corner, an out-of-date desktop environment in MATE, and in the other corner, Cinnamon fragmenting things yet further.
I want a "traditional" DE in the GNOME 2 style, I don't feel the need to have a tablet UI on my desktop PC with keyboard and mouse. But I'd rather not have to go back to ye olde software to do this. I'd like GNOME to take into account those of us who want to use the new technologies without pretending our 17-inch monitor is a 7-inch tablet.
After what GNOME developers did with GNOME 3, I wouldn't trust their classic mode one bit. Cinnamon devs clearly understand the UI needs of users, and Cinnamon is already superior to pretty much every DM out there in usability.
I wouldn't go so far as wishing them a speedy demise -- if building something like that makes you happy, who am I to hope that it comes to an end.
I do think that those projects will naturally and healthily die out, or perhaps evolve into other forms and directions. They're good projects, I just don't think they are as needed now as they were pre-3.8. And I think for most people, the basic desire/need to have a GTK2/GNOME2-based experience will largely be satisfied by GNOME 3.8.
