Maybe the Motorway is Wide Enough?
After the big move to virtualization in the past few years, maybe enterprises are finding that they can run a lot more on a lot less. Particularly with the ability to move compute loads now on the fly meaning you can run your infrastructure closer to your chosen utilization levels without service impact.
That, and "the cloud" starting to take off with Amazon and Microsoft services, business's only need to replace EoL tin rather than adding new.