In an MMO, there are weekly server and database maintenance periods, after which things often get better, but occasionally get worse if something with an update went wrong. Then there is a period of instability while the problems are fixed, and then things are usually pretty smooth for a while.
I had to go in today on a day our company is closed, because we had to take down a couple of servers to upgrade some hardware. We never could have done it while the company was open, because too many people use the applications and data on those servers during the work day. Our email was offline for a while, but that was unavoidable. No emails were being sent out, and incoming emails will still arrive, and no one at the company, except our annoying salespeople with their Blackberries, or anywhere else will notice the delay.
MFC never shuts down. MFC has to do the same type of maintenance occasionally, but they don't allow for an extended downtime because, unlike with MMOs, those would cut into the livelihoods of the models, who often are only able to work during certain hours. As a result, they try to do their maintenance and apply changes on the fly. Bad things can happen, just like with MMOs and there are unannounced restarts and the occasional crash, and things eventually settle down.
TL;DR: Shit happens. It happens for a reason, and it's occasionally unavoidable.