That convivial atmosphere is one of the things that originally set Lyft apart. More recently, they've tried to figure out how to balance that with people who prefer silence. http://thehub.lyft.com/blog/2015/7/14/giving-betterrides-gre...
I have found the exact same thing in Uber drivers -- questions like "How was your day?" are commonplace, and some have chewing gum or other amenities.
Sounds like a Colorado Springs effect. Here in NYC I've used both fairly evenly and (unsurprisingly) the experiences are fairly similar and in line with the typical "uber" style of sitting in the back and not talking unless you choose to reach out...
From my experience in NYC many drivers drive for both Uber and Lyft. In an anecdotal poll I ran with those drivers, they say Uber riders usually like to be left alone while Lyft riders are more chatty.
The major thing I found different was the driver wanted me to sit in the front and was much more enthusiastic about conversation. It wasn't bad but it was definitely different and somewhat offputting. Not sure if that was just a single event, but I wonder if each company encourages those differences in driver interaction.