Again, the movie is well done, the kids are great, and the clown kills are spooky. Aside from the kills and torment, what makes the clown interesting? Nothing I can think of. Not even those teeth from the ALIEN movies. I have not read the book or seen the other version. Perhaps chapter 2 will reveal something that motivates this character.
I was telling my kids, I didn't see a plausible explanation as to why X-Men had evolved into what they were, but that the character motivations helped me through that. Young Magneto seeing his Jewish parents taken away by the Nazis was a hugely compelling scene.
Hard to compare X-MEN to IT, but I don't understand the clown's purpose, yet. I think that would be somewhat important to convey to any viewer that didn't know the text version. Now, I'm going to wait a year or two for Chapter 2, and I still don't know if it will give me a reason to care about why this clown character does what he does.
Hard for me to ever buy into the "pure evil" arguement. Aliens (from that series) kill to defend or reproduce. Jaws likes to eat. Freddy was burned by parents, so he goes after their kids. I get all of that from the first chapter of any series. Yeah, yeah, the fire happened. I need more than that, before waiting a year or two.