I never really though of that, but that's pretty true. I guess that using a compiler is generally a lot simpler than using a database. When using a compiler, the majority of the time you're doing something really simple compilation, or you have a build system take care of the entire thing, where as the database requires design considerations. That would be my guess at least.
But I do agree that a database implementation course would be fantastic. It's one of the most important categories of software today for sure, up there with operating systems and compilers. My Uni was going to offer a course this Fall, but COVID has led to it being delayed. Here's to hoping it's offered in the Spring.