Most people I know signed up to pottermore to get sorted and then just forgot about it, anyone who enjoyed the books to some degree kind of wants to know what house they would get but really most people should already know; I'm a self-serving asshole, gee I wonder what where I'll end up, if only it was super obvious. I do agree though, there are some people that take that shit so seriously like its a defining part of them, I can't image introducing myself to people with an avalanche of "libra, slytherin, intj, Russian, Christian, Hetero blah blah blah".