I don't care to argue whether this is true or not, but I will highlight that the cloud business was nascent enough that Amazon had the opportunity to define it

I don't care to argue whether this is true or not, but I will highlight that the cloud business was nascent enough that Amazon had the opportunity to define it and they were able to bootstrap quickly because running a large data center was already part of their core competency. Granted, building a global scale infrastructure was an amazing accomplishment, but you have to concede it's easier when you're starting with a team who already knows something about the business.