In the old days, DB vendor independence was considered important, because the Free databases were not considered good enough for Enterprise use. It had to be Oracle or IBM. Even if you were starting out on MySQL, you wanted to retain portability for when you moved to Oracle. Hence building ORMs as an abstraction layer allowing vendor independence and more Enterprise-y Java.
There's also the "demarcation" issue. Traditionally databases were administered by change-averse DBAs who didn't want you stealing their CPU cycles to run your stored procedures, and were generally extremely averse to change.