It's hard to say what makes an issue/incident get to the point that someone in the media takes notice(in this case, Frontline).
While the program focused on Colgan and one particular accident, I think most observers saw the broad brush it was painted with.
For what its worth, there was an almost identical accident with an ACA jetstream 41 going into Cmh...about 10 years ago if memory serves. It hardly made a ripple in the news. (late night/early AM arrival...level off on the localizer after a descent..autopilot on ....throttles never advanced...resultant stall).
For some reason this accident has aroused more interest. It perhaps says much more about "us" than it does the media in general. Frontline, being PBS, doesn't have to dance to its Corporate owners and is more likely to have serious and reflective thinking programming. Any other network would be far more interested in the ratings it would generate than in a sense of public service or public good.( I would think)