Also usually you are on call every so-often so if your team/company happens to do this often it's not always you performing the deployment.
In regards to "being in the office": most people will do this from home after sleeping most of the night and waking up to an alarm and then coming in a little later the next day. There are a few hardcore ones out there that prefer to pull an all-nighter and do so from the office, although my mileage has been those are quite few and far between.
DevOps/Admin here! I prefer the all-nighter, but I've almost always (in 14 hours) done it from home unless physical hardware had to be moved (i.e. forklifted datacenter to datacenter).
If something goes wrong with your database, you'll be in a shitty condition to make fast and sound judgement calls.
One could say that not everybody's the same, but in those conditions I think that's not true. I've trained extensively under sleep deprived conditions in the military, where we were continually asked to make quick decisions in harsh conditions. Everybody's bad when sleep deprived and everybody's especially shitty at 5AM.
That sort of thing should be the extreme exception--anything else is just burning out employees.
By the way, one full time equivalent (that is, a hypothetical person working 24 hours a day all year long) equalled to five real people. That is, if they wanted ten people to be always available they had to hire fifty. You can easily understand why these arrangements are not common for Internet companies. Furthermore telcos have different requirements. Devops wasn't there yet and I wonder if it is accepted by management even now. My bets are against it.
I also wonder if companies like Google, Amazon and Facebook are organized in that way too.