A lot of people ride road bikes.

This is my current commuter, right after I bought the panniers and lowered the gearing. It was a sporty bike in the '80s, and while never top end, it would have, and could still if I take all the crap off it, meet the regulations for a massed start bike. If I strip all the crap off, I think it actually comes in lighter than my nice road bike - it's an aluminum frame and steel fork, without STI shifters, while the nicer one is steel and with a carbon fork and with STI levers and more gears. I have other bikes I'd rather train or compete on, but this one doesn't require me to put on funny clothes or shoes, accepts panniers, has fenders all the time, has low enough gearing to get all that up a pretty steep climb twice a day without undue effort, etc. etc. I also don't care as much that commuting in cities tends to beat up a bike.
My previous commute bikes have been an old 10-speed converted to singlespeed, a Trek 1000 sport/touring bike with a 2x6 drivetrain, like this one, a Schwinn Mesa GSX mountain bike (was my One True Bike at the time,) a Novara hybrid, and an old Motobecane badly converted with flat bars, working backward from the present.

This is my current commuter, right after I bought the panniers and lowered the gearing. It was a sporty bike in the '80s, and while never top end, it would have, and could still if I take all the crap off it, meet the regulations for a massed start bike. If I strip all the crap off, I think it actually comes in lighter than my nice road bike - it's an aluminum frame and steel fork, without STI shifters, while the nicer one is steel and with a carbon fork and with STI levers and more gears. I have other bikes I'd rather train or compete on, but this one doesn't require me to put on funny clothes or shoes, accepts panniers, has fenders all the time, has low enough gearing to get all that up a pretty steep climb twice a day without undue effort, etc. etc. I also don't care as much that commuting in cities tends to beat up a bike.
My previous commute bikes have been an old 10-speed converted to singlespeed, a Trek 1000 sport/touring bike with a 2x6 drivetrain, like this one, a Schwinn Mesa GSX mountain bike (was my One True Bike at the time,) a Novara hybrid, and an old Motobecane badly converted with flat bars, working backward from the present.