People like doing tricks on fixed because its a functional bike and the tricks are fun. No offense to any lurking BMXrs but I dont like riding thoes things more than about half a mile. I used to do a 4mi commute on one and cant tell you how awesome it was to get back onto a road frame.

On the subject at hand: some people are more comfrtable with risers. They are wider than drops usually and offer a perfectly functional hand position. Drops are nice because they offer the up top position as well as a few others. Im not gonna lie, I prefer drops over risers any day of the week and twice on sunday, but that doesnt mean everyone on a road/track frame should have to use drops..