This isn't strictly "evil DRM" as people are highlighting.
Unlike some other games, it's not like SimCity is just phoning home to figure out if it is licensed or not, and preventing unlicensed copies.
SimCity depends on EA/Maxis' server infrastructure for a great deal of storage and computation related to the macro-scale components of each game. Not only is city state synced there and shared between players, but regional dynamics and macro-scale economic systems are continuously maintained in the EA cloud. There's plenty of other features that are done server-side, and in total they represent a substantial piece of this game.
We can argue about whether these things should be computed and stored in the cloud, but I think there is a plausible, if imperfect, argument for doing so; Many players are involved and system resources are scarce relative to simulation complexity.
Regardless, the use of the cloud in this game is for more than just to deter pirates. That much is clear. And it's also clear that EA cannot "simply remove the DRM" and expect people to have a full offline experience; this is a primarily multiplayer game.
Indeed, this seems part of a trend in the games industry--that of bringing MMO(massively multiplayer online) experiences to more games. Call it social or something else, more games are working to get people to play with others. It's good business and actually creates some special experiences.
In any case, EA/Maxis have clearly not executed the launch for SimCity well. With 10 years of pent-up demand, it would have been wise to provision more server side resources to keep the experience good. It's hard to keep up with so many users, and perhaps a longer beta period would have helped.
But as a SimCity player and vet, I'll say that stripping out the online piece of this game doesn't make sense, and that piece was certainly designed for the benefit of gamers.
It's not strictly DRM or EA milking their customers.