This isn't meant to detract from your point, but just a fun anecdote -- my first job out of college was working on a product that had its entire business logic

This isn't meant to detract from your point, but just a fun anecdote -- my first job out of college was working on a product that had its entire business logic layer built in stored procedures. All of it. Hundreds and hundreds of lines per procedure. It "worked", but man was maintenance a bear. In a way, it was good; ever since I've been very comfortable with SQL. But I can't recommend it.