Only reason this show is rated R is because of violence and sexual themes. And honestly, the only bit that might have earned its R rating is in the first episode, the one bit from the trailer where the top of someone's skull falls off.
The actual writing, jokes, themes and otherwise of the show are not mature in the slightest. It's all written like a bottom of the barrel, bad kids' show that was written as a quick cash grab.
There's no reason for this show to be connected to Scooby Doo at all. For one thing, Scooby isn't present. For another, these characters have nothing to do with their original versions at all aside from the names, and similar outfits. So not only is it badly written, it feels like the original IP was used just to lure people in to watching it.