About at the transition between oracle 11 and 12, wmvare was quickly becoming the next big thing, and oracle licensing was causing concerns I don't precisely recall with virtual deployments. In conjunction with orm reaching good maturity and postgres starting to catch up with benchmark it was the perfect storm.
In a license audit, Oracle will charge you a full CPU license (currently $47,500/core for Enterprise) for every CPU in your VMware cluster, regardless if the database is running on it or not.
