Re: Remind me again why ...
Because it's cheaper for a small business of 30 people or less to pay Microsoft or Google a couple of hundred bucks a month to run all their email and shared calendars than it is to hire an IT admin full time and pay for dedicated servers and email software akin to the cloud offerings (standard IMAP just isn't the same).
Maybe it goes down a few hours a month but it's not the end of the world for the majority of businesses. Inconvenient and frustrating but not fatal. And the cost difference is substantial.