What I'm getting from most of these complaints is that the dozens of NYC running clubs need to meet whatever "grassroots" need that NYRR can't because of its size.
For example, if pricing is really keeping people from running, then the various NYC clubs need to put on cheap races for "serious" runners, seniors, minorities, young people or whoever it is that the complainers say is being priced out. Create some price competition and find out if there really is this underserved market. See what it really costs to put on a race in NYC.
I'm skeptical, however, that they would actually get high attendance at these races from people who couldn't afford a NYRR race.
As for the NY Marathon, it's a unique race. People from all over the world want to run in it and it costs a huge amount to put on, especially with the city raising costs significantly. High costs and high demand result in high prices. If you want cheap and hard-core, run the Yonkers Marathon, which has an even older heritage than the NYM.