Gap years were not common when I graduated high school (2008). Where I'm from, you graduated high school and went straight to a four year school. I didn't even know there was an option to not go to college straight from high school - for me, it really wasn't. No one I know went straight to community college - a few people dropped out of their 4 years and went there as they figured out what they were doing. A handful dropped out and went to trade school. I don't think anyone went straight there form high school.
A good friend of mine took a gap year for a variety of reasons - her father pushed her to apply to colleges that were out of her league and she wasn't accepted to any. Her parents had a nasty divorce years prior and were blaming each other, she was recovering from anorexia and felt herself slipping towards it again (a way of control that she lacked when her parents were in the process of divorcing), and she was overall miserable. She took a year off and worked at a shelter for homeless gay men in a nearby city. She said after working there and seeing what these men had been through and what they were going through, it opened her eyes and helped her see what was really important in life. She ended up going to a good 4 year after that, graduated, and is doing just fine. We lost touch, but she pops up on facebook every once in a while.
I think going straight to college was the right path for me, and I'm far less judgmental about gap years than I was (hindsight is 20-20!). A few coworkers have kids the college age that are struggling, and they as parents feel as though they 'failed' (that really is my areas mind set).