The question is, does it make sense for businesses with a handful of servers running their office environment, to a few thousand servers running production for a moderately popular web service, to pay consultants to drive out and tend the servers in their office closets/colo racks, rather than piggy-back on someone else's (mostly) well-oiled machine with economies of scale.
If you can build an in-house equivalent of the AWS team, do it. If you're going to pay someone to do it for you, AWS might be a better deal than your neighborhood business IT firm.