Coming out in March of last year and bugged with a myriad of issues relating to the game needing to be on-line all the time, it spoilt what should of been a great entry to the market, to the point where EA give away other games in its catalogue to apologize for how bad it actually went.
When asked about why it was done this way it was explained that Simcity was designed to be a on line game where Maxis could explore the interactions between players / smaller cites while offloading some of the work for simulating the city to the cloud.
Unfortunately some players debunked the latter and explained how an offline mode was possible.
I did enjoy Simcity once it was working but never really got in to the multi-player side of things, Me and Monsoon built up a region together but mostly we just built up our own regions and set them to private so no one else could join, which sort of felt like going to a party and putting on head phones and ignoring everyone and I just drifted away from playing it.
Now that we have a true offline mode where I can be antisocial in private it will be something I will returning too and pottering about in.
EA have done a quick overview of the new offline mode, which outlines the ins and outs.