>What I mean with an anti-aesthetics, is that they wanted the design to look good but not too good. They wanted a specific sentiment for the site and this sentiment excluded 'professionality'.

The right word for it is appropriateness I think. Texture created by randomness is appropriate in this case, of the kind you find in actual comic stores that get packed with stuff organically over time. Or think of your room when you were young, it's an anti systemic human touch.