The SingeDebile theory has got something going for it. There's a lot of people who have no idea how a bicycle is supposed to run. They have no experience with a drivetrain that doesn't make crunchy noises, they've never ridden a bike they can pick up easily in one hand, they think it's normal that the gears don't work.
So when they get on a fixed or a singlespeed for the first time they actually enjoy riding instead of finding it a chore and think that is the way to get this goodness.
Does that apply to the certifiable bike-geeks around here. No. But, we are a bunch of retro bike dorks and not the average schmuck who overpays for fixters on Craig's List. Those bikes are going somewhere folks.