Actually, I have to come clean. I liked the movie when I first saw it too. To be honest I still find it quite watchable, and catch it on reruns every once in a while.
I was a little surprised when I started hearing the bad remarks some were so vocal in making towards it. I liked the way it played against the stereotypes of the time, the light, easy, nature of it in the horror genre trappings, the jibes, and the odd outright funny remark or situation. Also I think there's a possibility it broke ground for a lot of stuff that followed. Clueless jumps to mind.