These things take time and 5 years is a blink of the eye
In large corporations the 5 year time frame has not yet given enough time to see the effects of Oracle's stewardship. Many of us are signed up for multi-year subscription deals and it is only as those come to an end that any thought of departure will arise. Once it does it then takes years to plan an execute the migration.
For myself we're just at the start of what will be a long journey away from Oracle WebLogic and onto open source middleware. It has taken until recently for regulators, auditors and high-up decision makes to get comfortable with the idea of using open source application servers for mission critical platforms in highly regulated financial industries. Now that we are happy with this move then Oracle will shortly be receiving the unwelcome news that we are not going to be renewing the multi-million pound contract.
I'm sure we can't be the only ones who are only just getting to this position?