Microsoft deserves a (dis)honourable mention in this article - just try to work out what you owe them, especially if you try to run any kind of application on Windows server in VMware...
As many posters agreed, all of these licensing schemes are designed only to maximize profit and wrangling space and try to make tie-ins look more palpable.
For example, to a CFO or just about anyone outside IT it would seem that MSFT and ORCL offer competitive virtualization platform, whereas in reality they're simply not worth the asking price.
Microsoft nominally gives Hyper-V for 0, however you must license Windows Server Data center edition, plus SCVMM if you want to actually use it, plus maybe you need SPLA (maybe not), maybe you need External Connector (maybe not)... . the list is effectively infinite and changes every 6 months or so, yet the value delivered is far less than VMware Enterprise+.