While you're right that there are fewer systems to manage and patch, you're wrong to think that normal enterprises want this. Change control means that anyone without an army of coders writing bespoke software for all the company workloads will want to patch each workload individually in a controlled manner to reduce business risk. This works for Google because they have numbers on their side, so each hardware image probably does only run one workload but maybe 50 instances of it. They would have sufficient hardware to allow failure of many hardware servers though so patching may not be an issue. They also have robust procedures for managing those changes while most enterprises do not, and backing out is often chaos.
The technology here and in virtualisation may be based on old technology but there are a significant number of new tricks which those old platforms can't do. There are also a number of things which make working with them unpleasant compared to the newer copies with updated tool sets.
Biting the hand that feeds IT
