I can offer another explanation for the perceived snubbing. That is--some people are just not very observant and are therefore oblivious!
With respect to the fixie crowd, there is an article (by me) in the current issue of Cycle California which may help explain this phenomenon. I aplogize in advance for this shameless self promotion. See link at: http://www.cyclecalifornia.com/
Stephen Bryne
Cool and windy today in Oakland, CA, USA