Anorak is a slightly harsh term. However its for the good of the club/car/brand etc that we have these people who have such passion and interest in them. If someone has spent a large number of years enjoying something, no matter what it is, they're bound to end up having strong opinions on these things, they're normally right!
They help us all out in many ways, where else do we find the info/data we need about parts, how they fit, numbers made, year differences, experience etc for free? I'm sure i'm not the only one who these 'people' have helped? All part of being a member of a 'club'.