pip is not a general operating system package manager, it's a python package manager. despite many users wanting it, distributing random packages which may or may not be python-based is not what pip is for, and clearly not what the aws-cli team wants to use pip for.

just because a customer wants something, doesn't mean it's a reasonable request. i'm sure there are plenty of people who would also like to install the official aws-cli through cargo, gem, or npm.