I think it goes hand-in-hand with the strict consistency mindset that Hibernate used for caching too.

In this article I explained that it's safer to switch to ALWAYS instead of AUTO flushing, as it's much more intuitive for Hibernate clients.

If one reads the JPA specs which say that:

(Default) Flushing to occur at query execution.

it's easy to think that query applies to both JPQL and SQL too.