I think people forget this isn't a sequel to the original
Everyone has major problems with this movie, but I have to say, ranking the whole franchise, this is the third best of the bunch scoring four and a half. The first two are the original, and Halloween III Season Of The Witch.
Yes, Myers was an established character, as was Loomis, Laurie and everybody else. They were established in 1978. But this isn't a sequel to the original franchise, this is Zombies own creation taking place in the Zombie universe. In the original franchise, the brother and sister storyline damaged it, and the original Halloween II was a mess that John Carpenter had to get drunk to write (seriously, he said that, look it up if you don't believe me).
Yes this movie is drastically different from the originals, but so what? The original movie is the only movie that happened from the original bunch in my opinion. Just babysitters stalked by a psychopath. What Zombie did, was he took themes from the franchise and made them work in a whole new and different style. The brother and sister storyline was evident from the start and worked in to the plot so everything made sense and worked. The first of these remakes was a bit dull in places i'll admit, but that was down to studio interference, not Zombie himself. The directors cut of H2, is honestly brilliant horror, and is immaculately shot.
Now, this movie is different, so why not make it something else entirely? Because then all you fan boys out there would blame him for ripping the franchise off. This is Halloween in an alternate universe. A different time line where they ARE brother and sister. And it works here. And it's a damn fine movie. If it was a sequel to the 1978 classic, no, i wouldn't like it. But it isn't, so get over it and just enjoy it for what it managed to succeed in.