And Starcraft II is an outlier, which is why it's always picked for the comparison. Plenty of enormous games took far less time to release (GTA5: 4 years, Witcher 3: 4 years, WoW: 5 years). Again, "release", not "get to the pitiful state SC is in".
Not only is it an outlier game; it's an outlier developer building on an outlier IP. It's a pretty horrible point of comparison for anything other than maybe Diablo III. Even with WoW being just in the works, Blizzard was already developer that had free reign and financial freedom to do whatever the hell they wanted. As development continued, with WoW raking in cash, setting a team aside to maintain some kind of pace on what would certainly be a good seller, almost irrespective of quality made all the sense in the world.
It's also worth nothing that SCII took 5 years to get ⅓ of the campaign done; the remaining two was finishing the other two thirds. It didn't take that long because the game was big or because it had tons of assets — even by mid-noughties standards — it's because they had to not just copy, but improve on the delicately balanced mechanics of one of the most popular competitive games ever. How do you improve on
Starcraft?! How do you even change it and not mess it up? That's where those first five years of its development went. Diablo is pretty much the same, but with the less successful idea of the auction house gumming up the works.
Compared to that, what's CIG's excuse? What have they been trying to hone all this time? It certainly isn't any of the stuff that took time any of those other outliers. Maybe some of it could be compared to what required an awful lot of time in LA Noire, but then, Bondi didn't survive that development…