My opinion is simple. 95% (ish) of men who post dick pics on their profiles have very little personally written in their profiles (some may have lyrics or something basic). To me, it's like saying "Hi, I have no personality and nothing to say! So here's my dick and that's why I think you should bang me!" Now, I know some are new and don't realize that it's not actually a turn on for many women, and I know this isn't true for everyone.. but in my experience, it's pretty common.