Having had my systems variously backhoed, struck by lightning, physically unplugged (backup and primary) by a sysadmin (cough who may have on another occasion been me not properly counting the rack I was on cough), and left without mains power for multiple weeks after an electrical fire in a substation, an outage is indeed something that can sneak up on you despite best intentions.
(yes yes "distribute" "build for failure" "it's apple we should expect more" are all valid answers, but wanted to make a tongue in cheek response to your wording.)
"are down" doesn't tell you whether it's intentional or not (whereas "outages" is a word that people don't use for expected downtime). "are having problems" and "are not working" don't even tell you anything about the symptoms. But "experiencing outages" means the service is partially or completely interrupted, and that it wasn't expected downtime.
"Are down" can also suggest that the downtime was deliberate.
Kind of a weasely way to say "are down," or "are having problems," or "are not working."
Like the outage is some kind of external thing. Hey we were just sitting here minding our own business and a random outage came by and jumped into our system.