I think many of us who have played the bar and pub circuit tend to fall back on artists that we either identify with or who have influenced our "styles". I know that when I was playing the bars I would frequently play Cat Stevens and Jim Croce songs because they fit my vocal qualities nicely. As time went on I found myself mimicking the artist more than singing in my own voice. This became true of songs by other artists such as the aforementioned Steve Earle and Bob Dylan. Over the years you forget what your own voice sounds like because you have spent so much time re-creating the music of others. It wasn't until many years after I stopped playing the bars that I learned to sing with my own voice again(quitting smoking helped a great deal as well
) I think if I was a songwriter things may have played out differently, but alas I have always felt more comfortable playing the songs of others.