Even aside from whether "rando" is contemptuous, the issue isn't that they don't have the same schedule: it's that they are not respecting the company-wide schedule, nor are they respecting fairly obvious norms of professional software development.
I'm a teacher, and I very much believe in educating people rather than putting them down, but jumping on a single phrase/term when there's nothing else to suggest contempt here strikes me as odd. It's especially odd when the entire culture of sysadminship has a reputation of eye-rolling and begrudging wizardry to protect users from themselves.
As far as the company wide/normal schedule goes, at my previous place of employment, major changes were routinely performed (by me) off hours on a Sunday with only relevant personnel on hand. This was primarily for B2B reasons where the vast majority of our clients were doing mission critical things from Monday to Friday. I don't feel that this was the case in these circumstances, which is why I completely agree with what was really said here, and with your reply was well.
I suppose my personal experience in this industry leads me to believe that small snipes like that uncover much deeper contempt than is revealed on the surface.
However there’s often a substitution for a more acceptable phrase when you relay similar information to management.
It’s perfectly acceptable in this context of a BOFH type story, which doesn’t care about the identity of the luser in question.
It's very very off putting and detracts from an otherwise good post. Makes the author sound like someone who simply has nothing but ire for their fellow employees.
While I agree with Rachel here at a high level, and have been a dedicated follower of her blog, I completely agreed with that comment. You shouldn't be shipping things in the manner described in this post, and you shouldn't be considering your coworker "some rando" and looking down on them for not having the same schedule as you.