This fun infographic from Bicycling magazine is from 2014. I bought a new commuter bike in 2012. I started shopping for a "commuter" in 2010. I got one off of Craigslist, but it wasn't the bike I wanted. I wanted a road bike with disc brakes. At the time, I lived on the top of Council Crest, I steep hill near downtown Portland. I needed a good set of brakes to go anywhere on my bike. 

I shopped and shopped. It didn't seem like an impossible request. And yet, it was hard to find. I ended up getting a Redline, a bike made in Seattle that got bought out by another company and no longer exists. It's a great bike, but probably not what I would have picked had there been more choice. Fast forward a couple of years and its hard to find new road bikes that DON'T have disc brakes! I was just slightly ahead of the trend. If I wanted to buy a commuter now, it would be a breeze.