Yes I have done a bit of riding fixed style and I do understand about the simplicity of the mechanics as well as the feeling of enhanced connection with the bike. But still I find the value of these attributes to small compared to the loss of true control over the machine during real world use.
I know your going to try to explain that because of the direct connection effect you actually have more control but it is my belief that very few people are skilled enough of a rider to be able to maintain control in emergency situations. Maybe you are skilled enough but is the average rider? I think not.
These bikes were designed to be ridden on a closed track by professional riders who would be capable of slowing and stopping the bike in a capable manner.
A perfect example of the danger of fixies in traffic is what I observed while in downtown Tulsa a while back. I was behind a truck at a red light, a rider on a fixie was coming down a incline street towards the light when the light changed. The truck started to move into the intersection before the rider started to slow, unfortunatly he lost grip on his pedals and had to make a panic pull on the only brake which was the front and he subsequently flipped the bike. thank god the truck driver did see him and was able to stop averting a real tragedy. The rider ended up with only scrapes but it could have been a real mess.
Could a more competent or alert rider avoided the incident all together? Probably. But I shudder to think of how many other people are out there riding bikes that are not,were not and never were made to be in traffic and don't have the skills needed to ride that bike safely.
I hope I never have to see a incident like that again.