SimCity Update 2

If I had to guess, the network communication design failed when presented with larger then expected number of connections, which showed poor testing being that EA has worked with online games before. There could also be higher then anticipated data errors (corruption from the network stack, cpu errors, memory errors) from the clients not in the beta that are holding memory on the server longer then expected in comparison to the beta.

Beta's don't always give the best information since the participants are self selecting (selection bias).

And making what is historically a single player game dependent on network connectivity for no apparent gain to the user is a design failure.