Why can't Scooby Doo have a Scooby Snack anytime he damn well pleases?

A thought occurred to me this morning: Although he's a dog, Scooby Doo is a fully sentient being capable of communicating with anyone else just as a person would. He's at least as smart (and maybe smarter) than his best friend Shaggy. Despite all of this, his "friends" use the lure of Scooby Snacks as either an impetus to get him to do something he would not normally do (such as go into a spooky old house) or as a reward for a job well done. While this treat dispersal technique is perfectly normal for any standard pet, it is far from normal for a partner of equal standing in a freelance mystery solving operation.

It can't be the lack of opposable thumbs, I've seen Scooby operate all manner of objects without the difficulty that one assumes would arise from missing those key digits. Is it simply because of Scooby's non-human status? I can't remember if Jabberjaw had a similar treat addiction, but if he did, it would be even more ridiculous. As a great white shark, he has a lot more weight to throw around when he wants something.

This treat dispersal frequency by personal whim makes the gang at Mystery, Inc. no more than common slave owners. I, for one, would love to hear Scooby say "Give me a Scooby Snack now, bitch!"

Maybe Scooby just has a really strong submissive streak. If that is the case, it would make Velma kind of a dominatrix. And that is pretty god damn hot.