I think this is an endless debate...
I didn't take lessons to start out on the guitar, and I have had a formal training, but much later in my life...
I am now a guitar teacher and I am glad that I have started out alone, because I was much slower, but still, when I have found a teacher, I knew what I wanted to play...

I have bad habits, I know how to play without them, but it's my style... I teach my students the right way, and when I see it doesn't work out, I show them how I use that particular technique, it helps them finding their path...