"Use our tool's language instead of the other tool's language because you don't understand the other tool's language well enough to use it effectively and efficiently."

Uh, what?

SQL allows you to do many things more effectively and faster than in-code. It's more than just a persistent store; it uses the power of math to do things faster. As an example, aggregation can be faster in the DB if your data is the correct shape (via group by).