Judging by dimensions
Disliking something someone likes
etc.
Real example of shapist
shapist: (insert shape here) is better than every other shape. I think that (insert different shape) people are disgusting and horrible and should die.
An individual that discriminates, or holds an unfounded bias against sci-fi movies, books, or fans. Typically anything space-ship, robot, or future related is the target of ridicul or strange looks from Spacists.