Exactly how many movies have involved kids fighting against a developer's plans to pave over a local landmark or skatepark or whatever with the help of a magical thing or critter? That's what half of the direct-to-video stuff on the shelves in the early 90s appeared to be at my local video stores.
I don't think there is any direct relation between the two, there are no writers, directors, producers or film companies in common between the two films. Probably just unfortunately similar entries into the "socially inept but nice children fight to save a(n) X from Y with the help of a(n) Z.
Bonus trivia: the woman two produced The Dirtbike Kid also produced Sharktopus and Dinoshark. 30 years of excellence! She does get a little slack from me though, for being involved in Chopping Mall...