>>82501136It's largely an exaggerated parody of old black-and-white serials that were falling out of fashion at the time, but still fairly common and very well known.
The Dover Boys are the flawless heroes, Dora's the damsel in distress and is largely presented as a literal object, and Dan Backslide's the archetypal mustache-twirling villain. While it gets a lot of names and basic premise from the Rover Boys book series, in execution it's mostly making fun of a popular style of film that the creators grew up with.
As to why there are so many smears, I think it was just to add to the ridiculousness of the whole short.
