This isn't scary? The first movie wasn't so scary, neither
I don't know why people bash this movie for not being scary, I found a few moments quite startling in it when I first saw them, like Paul Bunyan and the Witch, but the fear factor wore off quickly, like any horror movie. But then again, there were creatures in the first movie that weren't scary, neither, like the Leper, the Headless Boy, the Mummy and especially the Clown Room.
The only creature design that creeped me out the most was Judith, the Painted Lady. There's just something about the warped face and sharp teeth that is disturbing. Even after all this time, staring at a still of it still bothers me.
This is part of the problem, that these two movies are rated R/15 and yet don't have truly scary moments but plenty of gore, blood and bad language, but then I think that was always the intention, and that these movies were more about the characters and their attempts to overcome their fear and defeat evil. It was these character moments when Pennywise scares them that was the most fun and thrilling, with the "will he/won't he" threat of being eaten. This is what the writers and director intended.