I have a genuine honest question, and I am not trying to be ironic or sarcastic. Apart from track racing, why would anyone want to ride a single speed bicycle?
I will wait for your answers.

I don't and never have liked changing gears. Yes, it's an easier ride with gears, especially climbing hills...but I like the challenge and low maintenance of a single speed.

Why would anyone want to wear flip-flops unless going to the beach? Haha. It's all about preference man.

Ditto.

there are a lot of reasons. i'll name a few

simple - you can focus more on riding and less on "what gear should i be in"

less maintenance - if riding everyday in inclement conditions, there is way less to fail / get crapped up on a SS bike

lighter - less chain, shifters, dr's, cogs, chainrings, etc.

Sheldon said it best:
Fixed gear for Fun, Fitness and Form, Feel, and 'Fficiency!
https://www.sheldonbrown.com/fixed.html

They have great acceleration and are very fast. You can describe ss/fg in one word, Simplicity !!!

I live in Chicago and having gears is like driving a stick shift car. Its just too much of a pain.

a.) Simple, efficient.
b.) My bike never breaks. (knock on wood).
c.) Fixed gear = better winter handling (IMO).
d.) Fixed wheel doesn't have pawls that freeze up when you are 10 miles from home and it is -20F.
e.) Lighter. (not a big reason for me).
f.) Aesthetics.

i think riding fixed is like driving a stick shift and driving an automatic is like a singelspeed...the manual transmission is more engaging like the fixed gear

if you know what you're doing on a road bike, this isn't a problem.

my road bike weighs almost a pound less than my fixed.

This question gets asked a lot. I will wait for you to use the search function.

This is pretty much it for me.

I wanted to go back to riding bicycles, but I realized that I never changed gears all that often while riding, so I opted to purchase a fixed gear.

I have not looked back, and it is so much fun.

EDIT: I also planned to try out and make something of track racing.

I really need to make it to the track soon, but it is so cold and rainy here recently. :'(

but... if you slapped your fixed wheel on the road bike and tossed the rear brake, shifters, extra chainring, cables, and derailleurs, it would be lighter than your the fixed

Just sayin.

Isn't anybody gonna toss out the Z-word as a reason?

(By all means, don't.)

Seriously. I understand it may be an honest question, but putting in an honest effort is a good start.

t h e z e n f t w

If you have to ask, fixed gear probably isnt for you.

It's all about the scene though. Nothing else. The scene.

Shaun: Don't say that.

Ed: What?

Shaun: THAT. The.. zed word--don't say it.

no one is saying its a 'problem', its just that mentally there is less things to think about. With a fixed you hop on and go and pedal, no swtiching gears up and down all the time.

Remove all the gear stuff from the road bike and it will weigh less.

I was riding a somewhat heavy geared mtb, my friend let me ride his conversion, I loved it, and was in the market for a new bike. And since a vast majority of my riding during the school year is city(if you can call this a city) riding, shifting gears isn't that practical in stop and go city streets.

Curiosity perhaps as first, plus the bikes look really good. The novelty wears off after a few years and then you just choose the right bike for the ride. I don't prefer SS/FG to gears, I like them both, but a ss/fg forces you to adopt a different riding style, which keeps things interesting, and (I believe) they make you a better rider.

Plus I've found that I like hammering really hard on a fixed gear....track frames with symmetrical (undished) wheels are so much stiffer than road bikes with heavily dished wheels. They feel so much more solid when you stand and put the hammer down..thats what they are made for, after all. Cranking a fixed gear bike over a series of shallow rolling hills, keeping a fairly high cadence, has a better rhythm to it than riding a roadbike.

I use mine for training, even if I stick my road bike in one gear for an entire ride I feel like I get a better workout doing long rides on my fixed. Doing a century without coasting for even a moment is a great spin workout.

One thing I really like (to add to what has been said) is the quietness. Can't hear a thing on my SS (if I'm on a quiet road).

But in the end, it's just another way of getting to one place from another. I also have a longboard, running shoes, rollerblades and probably a razor somewhere.

a fixed drive-train simply feels good.

practicality for me. Living in a city, I would get nervous leaving my $1600 cross bike locked up outside a movie theater/grocery store/friend's house/whereever. You get a cheaper fixed gear, there is less to wear out, less time spent on maintenance, less parts for a**holes to steal/mess with when it is locked up. I like being able to just grab the bike, never have to deal with adjusting derailleurs, and never having to worry about someone stealing the bike when I am away from it.

If you worked on fixing up old houses on weekends would you haul wood with a Ferrari or a pick-up truck? (to me) riding a fixed gear around town is the same concept.

And some people prefer a pickup all the time.