Some people are in it for the challenge. Someone else's outage? Yeah I'll happily help diagnose it, analysing and figuring out where the issue is can teach you a lot of things.

For the record, this was never at night. Late in the evening, sure.

It really depends on where you want to steer your career. There's some roles, especially in management, where "working hours only" isn't really an option; if you aspire to one of those you've gotta convince people you'll do what's necessary.