Private Parts isn't a bad film by any means. The issue is it hasn't aged well given that Howard hasn't. We now know who the real Howard Stern is, if it was about anyone else other than him the film would still work. The film is a classic tale of humanizing this larger than life celebrity figure, telling stories of how they found themself and the kinds of adversity they faced as they worked their way to the top. He fights for those around him against what he perceives as wrongful censorship, and despite his radio personality being made out to be this disgusting pig we see that he is loving father in a happy marriage.
We also see things like him learning the boundaries between his personal life and the radio workspace. At the end of the day we see that this personality is just an entertainer, behind the scenes he is a normal guy who has a story we can all relate to. In real life however we have learned that Howard is a power hungry egomaniac who screwed over many around him while selling out when it became convenient. He was the definition of safe edgy. For all his posturing now about being a good human being deep down we know he is a creep like many other personalities who base themselves around being edgy.
In real life the happy family man actually had his family life deteriorate badly. He also never learned any serious boundaries about personal issues and the radio considering one of the reasons why he had the falling out with Jackie is because he forced Jackie to broadcast his marriage troubles on the air. He also paraded around Artie Lange and his degenerate behavior for years until it started to negatively impact him.