It's the best decision, really. I know EA is the usual scapegoat because all of the issues, but let's be blunt here: maxis agreed on those. And whether it's because they didn't knew better or were downright forced into it by EA doesn't really matter when the end result are games that are strictly worse than their predecessors (I'm talking both about simcity and the sims here).
It's certainly sad for the developers, but I doubt they'll remain unemployed for long (if at all). In the worst case, we'll see a simcity or the sims clone (with a different name 'cause EA own it) on kickstarter within a year.
I'm curious what kind of lessons EA will learn of this. Surely they'll understand that their yearly sports/COD 'update' won't remain a gold mine forever.
Oh, and...aren't there plenty of decent city building games by now? Cities XL, cities in motion, Anno, tropico...I'm not too familiar with these kinds of games, but I'm sure the loss of a future simcity game isn't much to mourn over when there are plenty of alternatives available (not sure about the sims, though).