I'm still using my copy of Office2008. It still works just fine. It never has an "authentication outage". And, as a bonus, it costs me nothing to continue to use it. I would feel sorry for all of the poor shmoes who are locked out of their office suites, but I'm sorry, you brought this no yourselves when you accepted a subscription model. If people just said no to the subscription model, no one would have this problem.
I don't think the complaints are about office suite access, as that has a fallback in case of failed auth. It's more about IM/VOIP/email, OneDrive/SharePoint, Azure cloud, etc.