I didn't like it either, but Blazing Saddles and The Producers are some of my favorite comedies ever so it's not that I don't like Brooks' comedic sensibility. I just didn't find this particular movie very funny. It might be because Blazing Saddles and The Producers have more depth to them and Young Frankenstein is more akin to a quaint parody and that's all it is.

Comedy is the most subjective of all genres so it really isn't any wonder why it doesn't connect with everybody the same way or even a large amount of people like drama does. You needn't put people down for finding it funny, that's just immature. But feel free to dislike it all you want, by all means.