[quote=Esper]
Why not just accept others for their personal preferences so as long as it harms no innocent?
[/quote]

Because normally those who are not into anything like geek/nerd culture will see it as something to attack and mock people for liking.
Those who are open minded enough to simply accept a difference of preference have already shown themselves to be not normal simply by being open minded.

In other words to clarify, when I say "Normal" I don't just mean '"You're not a geek/nerd" but "You're not a geek/nerd and will attack and criticize others for it. Therefore not worth my time".