It's interesting that they did this. On the one hand, I miss seeing what they were doing, but I come down on the side that it's the right way for them to approach games.
The first thing I think of when I think of Blizzard is a company that does seem to care about quality games.
It's funny, even when their senior people have left and made games, it doesn't seem to have gone as well - Diablo II team making Hellgate: London.
One of, if not the, earliest Blizzard games was 'The Lost Vikings'. I think it's the best platformer I ever played - at least of that period.
Diablo was very innovative. We take action RPG's for granted, but Diablo was a pretty big deal in new things.
I didn't care for Warcraft III, but it seemed to really push that genre as well.
Warcraft II, StarCraft - seemed to be the 'best quality' of their genre. Hearthstone I haven't played but seems very well received as a card game.
I can't think of another gaming company with their record of putting out games that good so consistently. So, good for them - for investing in it, and deciding not to do it.
Maybe some of this isn't just about that, maybe that's spin to cover up 'they don't think the MMO industry is that profitable for another product', who knows.
I would like to see something fresh done with MMO's. The holy trinity, the quest-based gameplay, they could create something innovative in gameplay.