As far as I can tell, this idea is popular but it is flat-out wrong. I seriously don't understand how this criticism makes any sense.
The first Kotaku article you link quotes Maxis general manager Bradshaw: "GlassBox works by attributing portions of the computing to EA servers (the cloud) and some on the player's local computer." She was speaking in the context of online play and region play. There is a bit of ambiguity here, but suffice to say given the context and a modicum of common sense that the servers run the region-level simulation. Nobody has ever presented a single shred of evidence to refute that claim. The servers run the region-level simulation.
That is why the region level simulation is not playable in offline play. Because the game isn't playable offline. Because the servers run calculations.
I was upset that I couldn't play Sim City when it came out, and I am still upset with continuing region sync issues. The pathfinding code for agents (vehicles and utilities) is abysmal. There are lots of valid reasons to dislike this game. But misrepresenting online-only play isn't among the things EA did wrong.
EA built Sim City around region play and they told the truth about that. They say it doesn't work if you're not connected to the region, and when some folks show that, indeed, the region sim doesn't work when you disconnect from the internet, it's total bullshit to construe this as evidence that EA lied about whether it works offline. It doesn't.
Are people simply upset that EA won't make some kind of boneheaded mea culpa? "We built the game around online-only region play as cynical ploy to prevent piracy." Yeah right.