As you might imagine, during this exercise, we've had a lot of conversations about the points you raise. We have our own opinions, but we ultimately removed most of that content from the blog post because we didn't want it to be too editorial. We will be posting follow ups with some of our opinions.

Some things are really difficult to answer in a vacuum. If you already have a competent devops staff, hosting your own hardware is probably beneficial. The increased performance per "server" is substantial. But no devops staff? Then it's either very risky or cost-prohibitive to own hardware.