As one of the loud "anti-cloud zealots" out there, I agree with you that this is actually a workload-dependent decision (or a luxury product that you can buy to show that your company is rich and modern). I think a lot of big companies are going to be moving toward "hybrid cloud" in the near future if they haven't already: maintaining a few racks (or an entire DC) to handle their base load and then doing bursts of heavy computing in the cloud.
The days of the full cloud lift-and-shift are going away, and we're getting to the point where people make that decision rationally.
As an aside, I actually believe in the cloud enough that I am working on a startup for a piece of cloud infrastructure.
