Shiva, the greatest teacher, takes the Bhasmeshwar form to show to the world the futility of attachment and desires. Bhasmeshwar means one strewn with ash. He is at perfect ease being Himself. He has negated all socially accepted rituals and behaviors. He has detached himself from everything.
Bhasmeshwar form of Shiva is the origin of the concept of the Avadhuta which was popularized by Lord Dattatreya and by many Saints.
Ash-smeared Shiva roaming cremation ground is one of the most famous painting used to depict this form.
Shiva is the Supreme Truth and he extols through the Bhasmeshvar form that all that we hold dear, including our body, even the universe will one day turn into ash.
Once this supreme truth is understood, then working and living society will become easy. We will not be bothered by false ideas of approval and social acceptance. Such a person will be more creative and helpful to the society.