For me, I guess it was force of habit. As a former newspaper reporter, I use my name for my bylines. I saw no reason to change. I use my name on Facebook and LinkedIn. if I log into a game site, which has been years, I will use some made up name, but I cannot remember the last time I logged into one of those sites.
I will people use their names and I wish people had to use pictures of themselves instead of clip art characters. Putting a face to a Hub or a comment might make some people a little more professional in their responses. At least, that is what I have found.