Because I've never had a database engineer available to create my schemas for me. And frankly, I've never had a problem designing or maintaining a schema: it's not rocket science. Writing queries and getting performance out of the DB, that can be rocket science.
> Writing queries and getting performance out of the DB, that can be rocket science.
I tend to ask questions more about database internals, but it's a crucial job for an engineer to understand how to get performance and integrity for their queries.
Sometimes times you may get world-class DBA/DBE (my current employer is one of those places) who can do an engineer's job (in terms of tuning the queries, etc...) but that is really an engineer's job.
