Why not? You're asking a question, of sorts, and getting an answer from the result. That's the literal definition of querying.
> Grabbing all the docs in the db into my controller and filtering down that array is what Firebase makes me do instead of writing queries.
A query language is just an abstraction. One you can have in your code. At some point you still need to "grab all the docs into a controller and filter them down", though. You could push that step into the Firebase service, but it would still have to do the same thing you're doing. There is no magic.
Better would be to provide something indexable so that you don't have to go through all the docs, but you can't index that which does not exist.
But I can’t.