I think Universal painted themselves into a corner in a way. The even though we love the HOUSE movies, the mistake was putting all the monsters in the same film to begin with. Once they did that, it was very hard to turn back not only for the sake of continuity but also because the audience might be let down that there was only one or maybe two monsters in a film.

I can see Uni being short sighted and only trying to top themselves after Frankenstein Meets The Wolf Man. "If you thought two monsters were great, wait until you see three of them together!". When what they really should have done is only do the occasional match up, then go back to individual monster stories. But once they had that 3 MONSTERS idea, they had extended themselves too far. They weren't even sure what to do with them all in the same film, the best example of which HOUSE OF FRANKENSTEIN came off episodic. The three monster battle royals ended up hurting the series more than helping it, because as I said they ended up writing themselves into a corner.

The two monsters that had the most in common, Dracula and Imhotep The Mummy, would have been great together but the chance was lost to match them up. That chance had passed somewhere between Ghost Of Frankenstein and House Of Frankenstein.

Selling the great monsters down the river to Abbott & Costello even further painted them into a corner. Once the monsters had become a laughing stock in a comedy, no one could ever be truly scared by them again.

Even though the monsters series could have easily gone on another 20 years, Universal killed them inadvertantly by being short sighted and having bad ideas.

--Rob