
Efficiency?
"... configuration management databases, because they all improve efficiency".
ONLY if these are kept up-to-date and with the correct information in them. And in my experience, that doesn't happen often enough. CMDBs are usually out of date and incomplete. Decisions made on such data is subsequently flawed and takes an age to sift through (you have to assume all data is incorrect until proven otherwise). Some of the CMDB automation tools extract garbage with their default config, and also need attention to ensure that that doesn't happen.
And yes, some PHBs are using virtualisation to avoid upgrading old and out-of-date infrastructure. I've seen it on more than one occasion.