Why Halloween (2018) Is Scarier Than You Think
2. Trying To Explain The Inexplainable
Halloween makes an effort of proving that Michael Myers cannot be explained, and goes so far as to kill those who dare try. Not only does this appear to be some sort of meta commentary on the previous evolution of the franchise, where various motives were ascribed to the character, from Druid cults to broken homes, it also serves a purpose in restoring The Shape to true bogeyman status.
Early on in the film we are introduced to the character of Dr. Ranbir Sartain, dubbed contemptuously as "the new Loomis" by Laurie. Unlike Loomis, Sartain is completely and utterly fascinated by Myers, to the point of obsession. It's heavily implied that he manufactured Michael's escape, and he does it all in a vein attempt to understand his personality. The issue here, of course, it that Michael is pure evil - the kind that no one could ever hope to rationalise, explain, or explicate.
Any attempt to understand Myers in this film is met with aggressive violence, and that cuts to the very core of the character. He does what he does not because of any particular drive - he is just evil given human form. That's far more terrifying than anything an origin or convoluted backstory could convey, and it's partially why the new film is so unnerving.