Because they say bullshit and come up with the silliest , most bullshit stories of their lives of crime fighting. Like Joe Pistone and the myth that he was so close to being made. How, Sway, How? Considering literally everyone outside of the Sonny Black crew suspected him of being an UC? You think Galante or Rastelli wouldve held a making ceremony for him? Especially Rastelli, with Massino having his ear and all, and Massino being among those who knew he wasnt right. Balistreri cut contact with Lefty, Sonny Black, and that entire regime because he suspected Pistone of being a rat. People like him, tend to overstate their importance within that world. Also shows you the type of brokesters Sonny Black and his guys were, they were desperate for a money maker, that they were willing to look past the obvious, like his silly, unrealistic, non-Italian name of Donnie Brasco, just to make some bucks and enhance that crews little sphere of influence.