Well, briefly since I am really sleepy and must crash soon, John Carpenter originally intended to make each Halloween film 99% unrelated to the previous, linking them up only with very tenuous plot threads, but with each based around Halloween in some way. Trouble was, the studios got the first sequel made with Myers. Carpenter had very little to do with it - it was directed by Moustapha Akkad, who has directed/produced pretty much all the sequels as far as I know. Carpenter wrote and co-produced H3, staying true to his vision of unrelated sequels. Unfortunately, everybody said "Where the fuck is Michael Myers?" and the movie flopped. The studio suits, who had created this expectation with the first sequel, felt all vindicated, and never-fucking-ending Myers sequels were born.
As far as I am concerned, Michael Myers has long outlived his usefulness. He has become dull - not a joke like Freddy Krueger did, but dull none the less. He was a wonderful boogeyman in the original Halloween, and still fairly effective in Halloween 2, though it was a terribly inferior movie compared to the original. Carpenter saw it coming, and tried to get the series back to what he had originally planned, but it didn't work. Sad, really, since H3 is really quite a fun horror movie, with some great scenes and a really kick-arse ending.
Counter-rebuttal?