Houdini has a few tighter-than-average shots. Some weaker players struggle with those shots and instead of being motivated to improve they sell the pin. Some go as far as to blame the pin for their lack of aim by saying the geometry is broken. Probably best those types get a Monster Bash instead.
Maybe Ericpinballfan is onto something with his instant gratification generation remark.
Personally, I really enjoy pins with some extra-challenging shots, including Houdini. Who wants a pin with no challenge, where Grandma can step up and roll the thing? Apparently lots of people.
Think about which you camp fall into and choose accordingly.