Anyway, if you don't want to buy a support service, either from Oracle or any of the other companies that sell it, the use of the JDK is free. There is no "enterprise" flavour of the JDK, paid features, or use restrictions as there used to be under Sun's management. Java is obviously freer now - as in beer or in speech - than it was 20 years ago.
While everything you say sounds true, it’s not free - it’s gunpoint, it’s a lie, and if you’re big enough Oracle will come after you for subscription fees.
RedHat does the same crap. Heaven forbid you run RHEL on RHEL in containers, you’re gonna get fleeced.
You can run unlimited RHEL containers on a subscribed RHEL system. It's even set up where if you run a UBI container (a redistributable subset of RHEL content) on a subscribed RHEL system it automatically upgrades to full RHEL.
The idea there is that it's cheaper for companies with legacy software that isn't actively maintained to pay for some portion of the performance improvements in modern JVM generations than to ramp up maintenance to upgrade to modern Java, and this can help fund the continued evolution of OpenJDK.
IBM kind of thought of it, but ended up withdrawing the offer.
So the anti-Oracle folks would have seen Java wither and die in version 6, and the MaximeVM technology would never had been released as GraalVM.
No pre-core fee needed.