They wouldn't expect any redundancy in an alarm system monitoring centre? Also there's a very brief instance in time where such a system would not be basically digital.

I think a lot of systems have lost a lot of reliability and resilience as they are replaced by (centralized, virtual) digital equivalents.

Having a doorbell that fails because someone made a typo in a DNS entry (or whatever it is this time) is silly and people have every right to be angry. Though it would help if they direct some of that anger towards themselves for subjecting themselves to a doorbell that they don't control and sends surveillance on its immediate surrounding to some third party (who may send it back, for a price).

That's an interesting observation, but I don't think it's because of the instant-outage-notification thing.

It might be worthwhile to look at how peoples' expectations of service availability have changed in the last fifty years as compared to peoples' perceived importance of non-essential services.