Well, 3 years is a long time (though some of your concerns may still be valid). That said, the point of comparison is between the two platforms as they are today.

> unless a platform is doing work outside of “the server”, I don’t believe it can offer hard multi-tenancy.

I admire the work AWS and others are doing to harden the hardware base, but I'm not sure how software would contribute or not contribute to that line of defence.