The copy that a business would send us rarely made air. I know, because I was often the person who rewrote it.
Example: At a talk radio station I worked at a number of years ago, we received a press release from a person who was protesting John McCain's policies in a very particular way. It was very positive, and spoke of his mission, and blah blah blah. We had no clue who this guy was, but it tipped us off to a great story; we didn't cover it in the news portion of our broadcast, but the talking heads that evening had a very good time pointing out how ridiculous it was.
This is how news works. PR helps a producer by bringing their attention to something, because let's face it, omniscience is not a trait of local news producers. The producer might help PR with a bit of coverage, or very likely doesn't. (The fax machine at a local newsroom is hilarious to watch.) The angle that gets covered is occasionally not what PR wants. This relationship is push and pull.