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.