I am currently single speed, largely because the hills here require 140+rpm descents on a fixie. There are still a couple of things I prefer on a fixie, although this is just my opinion.
When riding on ice and snow the fixie keeps me more aware of traction or lack thereof . It also allows me to shed speed when my rims are wet or icy and the brakes don't work well.
I am very familiar with the bike routes in my little town and unfortunately fall into a Zen autopilot state in which I am not vigilant. As we know, vigilance is not only the cost of freedom but also is a requisite for avoiding accidents. Riding fixed requires me to pay attention and so is safer, since inattention by me or car drivers have caused all my accidents.
It's fun to have that direct drive connection with the bike. I like chicken but a big bloody steak is tasty too.