City restraints are coming from two problems:
1. The agent system behind glassbox scales badly when you increase the map (more agents, and each agent will require more CPU for pathing due tot the larger map)
2. Since we are supposed to play in multiplayer you can't have different map sizes, it would make the game unfair.
So from their perspective it will be like: either grannies laptop can run 4x4 or nobody will.
And as mentioned above the online requirement is there for anti-piracy, the tech is designed to require online servers.
For me it's a two-edged sword, on one side it's good that it might persuade pirates to buy the game, meaning more $$$ for future simcity content, and an incentive for EA to keep making games like these.
On the other hand it leaves me as a consumer at their mercy, they can shut down the servers rendering my product useless. In general 'always-online' adds more negative things compared to positive.
The city restraint is primarily a scaling problem with the glassbox engine, and unrelated to DRM.
But since were all supposed to play together it will be hard to give the extra space to computers who could run bigger maps.