It's not a coincidence, no, because Oracle can provide support guarantees in a way a Postgres contractor can not.
This is also a factor for independent developers (who build airline reservation systems) who need to choose a RDBMS for their product - they'll choose oracle, because ... Oracle can provide support guarantees in a way a Postgres contractor can not.
Which makes Oracle not a different class of product than Postgres, but a different class of support for the product. (which could be considered part of the product, so ... maybe you're right)
This is also a factor for independent developers (who build airline reservation systems) who need to choose a RDBMS for their product - they'll choose oracle, because ... Oracle can provide support guarantees in a way a Postgres contractor can not.
Which makes Oracle not a different class of product than Postgres, but a different class of support for the product. (which could be considered part of the product, so ... maybe you're right)