I wear cycling jerseys for commuting because my route is kinda long (15km) and so far I can't do it in less than an hour without sweating so commuting in working clothes is just not practical for me. But I participate in a local urban cycling group, who organizes after-work group rides, and I see a lot of downtown city commuters who don't use cycling, or sports specific, clothing.

But we do favor MTBs and Hybrids here (I have a trek Skye with skinny tires myself), maybe because there are cheaper models available in that style and are more widely known. Fixies and SS are a new appearance in my city.