If you are always hard on yourself, you will always be controlled by the past, and not see yourself for who you are now or who you want to be. You will always have regrets and insecurities, and blame that moment on a character weakness. Shame kills all chance for forgiveness, hope, and total change. It also kills freedom, creativity, and truly being one's self. Plus it's more fun being your shameless self, than living someone else's life. I believe the most inspirational and badass people in the world are shameless, or else they would have never got to where they are now, or where their legacy lays in history.
"I'm not in this world to live up to your expectations and you're not in this world to live up to mine." - Bruce Lee
Most people are called shameless because they choose not to follow the norms placed upon them by society. And, when those people go against those norms, they feel shame. One such example, is keeping up with the latest fashion trends to be liked, respected, and presentable. However, the money and time going towards the outerwear could be spent on something far more of value. Also, most clothes are made in by those who are under compensated with little to no civil civil rights.
Without shame, I can do whatever I want with my life! I can do a stand up comedy show! I can sleep all day and not do jack! I can even OD on Red Bull! YAAAY! My point is that shame is nothing but a burden on life's quality. Without it, life is a lot more fun!
Without shame there is no mechanism by which we would have any reason to act in a morally right manner. That is not to say that shame can't be a bad thing, as people can at times be ashamed of things they shouldn't be, whether because they aren't at fault or they try hard at something and fail. Shame can be bad, but to be shameless izis worse.
Having no shame can lead to erratic and careless behavior. Having some shame is beneficial because it can be utilized in a way of which an individual will police themselves. People who are considered shameless usually are so because they have no boundaries and will allow themselves to do things simply for shock value. It's much better to employ self-control and humbleness.