Because, as I said originally, there are multiple types of DBA, and what you describe is the code-centric data DBA under the thumb of coders. No real DBA, who's learned Codd and SQL and ..., has any desire to kowtow to coders, who generally make more bugs than features.:-P Building an Organic Normal Form™ schema isn't something that one guy/gal does over lunch, while the coders are playing frisbee. It's real work, with real payoff. That payoff being smaller data footprint, and loads less code on the client. Aye, matey, thar's the rub. Coders never want to hear about a tech that makes less code.

Again, for those coders who just want a simplified I/O syntax, and are too lazy to write their own I/O handlers, and want easy backups, then a sql database will do that. But it won't be very efficient, and will end up with spaghetti everywhere.