What is going on here?

I recently watched the roast of Larry the cable guy on comedy central, and one of the comedians made a comment asserting that Larry sold his soul to the devil in exchange for the acquisition of fame and fortune. I don't believe in the existence of any sentient being, malevolent and benevolent alike and try to stay above those sort of baseless hypotheses, but my curiosity does get peaked at times, which may transgress my better judgement. It wasn't the comment itself, it was the fact that this assessment is ubiquitous throughout the entertainment industry, that celebrities have sold their souls to acquire a lavish life, its tenuous, but its there. And they openly admit it nonchalantly. At first I figured it was just a saying or recurring joke when it was assimilated into music and even interviews, but through much inquiry and scrutiny I saw that this allegation has been made against many, particularly musicians.

The first was a 15th-17th century violinist whose name escapes me at the moment but the story originates from the allegory of Faust. Then, Robert Johnson, whom many consider to be the father of rock and roll allegedly sold his soul as well. According to the people who knew him personally he was a horrendous guitar player, so atrocious in fact that on a normal outing with a guitar in hand at any party, he received incessant complaints from his peers. He left his home town and when he returned a month later, he was one of the greatest guitar players the world had ever seen, which was mind boggling to many. He indirectly admits to selling his soul in exchange for becoming a proficient guitar player in many of his songs. Bob Dylan admitted it on camera without any hesitancy whatsoever, but for the most part it remains confined in the songs of many contemporary artists in anecdotal verses and subtle hints.

It nevertheless perplexed me at first and still does. Any thoughts on this?