it's really simple if you think about it
The NRA has money, power, influence and clout because of it's membership. If more people join, the organization has more power...
If people don't renew their membership, they lose power, money.....
The NRA has a vested interest in being moderate, therefore appealing the greatest number of potential members, therefore attracting more money, building influence, etc.
If they take a "hard line" (meaning a reasonable stance on the continued erosion of our rights) they're branded even more in the press as extremist, and may lose members, money, power, etc.
The other organizations are small, less powerful, and have less to lose, and appeal to the "hard core, right wing conspiracy nut cases..." and have the influence they do because they say what the NRA won't.
JPFO, CCRKBA, GOA, etc. will never have the kind of power that the NRA has UNLESS people join, including all of us on this forum.
Join the NRA, and then join another organization as well. As these smaller organizations grow, the NRA listens.
Just my .02