So he's selling Proof-of-Stake staking as a 'cloud' service? WTF?

Why would anybody choose to centralise their wallet on his 'cloud' service when you can easily download a PoS wallet and just have it running on a regular PC and staking as it should?

That's the whole point of PoS coins, to eliminate the need for constant PoW mining. It makes no sense to run a PoS wallet on someone else's server, unless you were trying to convince people you were selling them something they were quite ill-informed about and didn't realise the absurd nature of what was being shilled to them.