sorry but that seems really naive. an SLA is not a guarantee of service -- you can't force a computer or network to stay online because someone with a sheet of paper said so. it's a target for a best-effort guarantee and when that guarantee is broken then you get a bit of a refund.

it's like when you have a big building project and there's a provision that the contractor will refund $5000/day for every day past march 1st. doesn't mean march 1st never gets passed.

failure modes in the cloud are known too: your VMs are either working or they aren't, or maybe they're somehow degraded but you should fail over anyway. it's very similar to physical hardware. what will you think when a backhoe takes out your datacenter's fiber for 10 hours? that physical hardware and datacenters are now unreliable too?

as for a database that runs on a system that offers no guarantees -- isn't that all of them?