No one likes new characters in Scooby-Doo. Good idea, bad idea, more sense or not. Scrappy did save the franchise in the 70's strangely enough... but when's the last time you heard anyone talk about Scooby-Dumm, Yabba-Doo, Robi the robot, and Flim Flam in a positive light? It needs to stay the core 5.
Though... eh... I like Scooby-Doo.
I wouldn't hate talking dog movies if they weren't so obvious. Butt sniffing jokes got tired after the first one. The Buddies are just stock personalities that say stock phrases with nothing original or clever about them. They still have the oh so hip 90's style hip hop speak character 50 year old white guys with ulcers swear kids like unironically.