Given the "entitled customer" incidents I've experienced, seen, and heard about, "scheduled maintenance" sounds intentional and like something "you shouldn't be doing when I want my ice cream", where "broken" sounds like something the guy behind the counter can't help.

I'd be willing to bet that "broken" is just less likely to start a fight with an enraged customer whose day was very slightly inconvenienced by their inability to consume extra junk food.