Because you have a vendor/customer relationship. The big thing for AWS is employer/employee relationships. If you were a larger company, and AWS goes down, who blames you? Who blames anyone in the company? At the C-level, does the CEO expect more uptime than Amazon? Of course not. And so it goes.

Whereas if you do something other than the industry standard of AWS (or Azure/GCP) and it goes down, clearly it's your fault.