According to Grandy, the decision was made, in part, to differentiate the show from the children's favorite. "We couldn't get a take on it that was like, 'How do we kind of do this in a fun, modern way?' That felt like what made it a kid show was, Scooby-Doo," he explained in the panel (via Insider).
What made Scooby-Doo a kid show is Scooby-Doo. We couldn't have a take on it, like how can we do in this fun and modern way. [Our efforts] coincided with Warner Bros. Animation saying we can't use the dog!