The big idea behind BNC is to replace career politicians with real people who have actually held a job at some point in their life, and have some grasp on the reality everyday Americans face.
Congresscritters are so inured and shielded against facing the everyday issues everyday people face - healthcare, transit, rent, job searches, etc. - that they spend their time dealing with moronic statues in parks, rather than addressing anything of material value.
In addition, the longer you are in Congress, the less work you do. As you become more senior, more of your time is taken up with fundraising and meeting with lobbyists, because seniority = power.
If you replace half of Congress with actual Americans who have had jobs (recently) and lived in the real world, the thought is that the cycle of politician-lobbyist-fundraiser could be broken, or at least drastically altered.
In short, the system is ineffective. Small changes (See: Tea Party) will have no meaningful effect.
So BNC is attempting to address the problem in a big way, that is statistically and practically possible... it just needs a head of steam, which is hard to drum up when people are so politically tired, right now. And this may be its biggest hurdle. But, hey, when something goes viral, change can happen realdamnquick. So maybe there's a chance...