Next you'll be claiming SQL is a "full-featured" programming language.
> You seem to be trading one lockage for another.
If you want to look at it that way. But there are some significant differences between the two:
Database:
1. Should be a commodity, but isn't due to vendor stubbornness.
2. Difficult to write (I don't mean the SQL, I mean the DB engine).
3. Extremely performance-critical code.
4. Monolithic in design.
5. Done to death, and yet
6. Significant differences between the implementations.
App framework:
1. Written in a high-level-language, so it's easier to maintain.
2. Open source--tweak to your heart's content.
3. Any given subsystem is easily wrappable if swapped out.
4. Open to experimentation, as different apps have different needs, and yet
5. Not an awful lot of difference between implementations.
I've considered swapping out templating engines, SQL mappers, object caches and indexers. None of those tasks seems particularly difficult. Have you noticed the core of Dejavu is only 1700 lines including inline documentation?
Seems I've got a good glue, not a lock.