There's a significant difference between being able to run software "in the cloud" like how Ubiquiti instructs end-users to install Linux and then UniFi on EC2 and having the entire platform "in the cloud" and ready to use by the end-users with the operational cost rolled into the purchase price/support contract.
Requiring end-users to launch EC2 instances is missing the point of easy to deploy & maintain.
Ubiquiti is working on providing the controller "in the cloud" under the latter model. You can register and use their hosted system for mFi right now. Other stuff is coming.