I'd like to counter that it never had a serious chance. Their goal is laudable, however attempting to box up inherently complicated software into something that your average end users can handle is just not feasible at this time. Threats are constantly evolving, websites constantly changing. This is like trying to hit billions of moving targets at the same time.. good luck with that.
There is no way for your average user to weigh the security tradeoffs necessary to make an informed decision, so what would end up happening is they'd get a FreedomBox think they are safe then very quickly disable things until all their favourite websites work again. This is far worse than doing nothing as they would *think* they're protected when in fact they are not.
I think this could be possible with some sort of business behind it providing a subscription service that keeps the list of exceptions as tight as possible while still allowing customers to visit the sites they need.. Supporting that would be a costly nightmare due to sites constantly changing things, I don't think that plan would work either.
The only way I think it would work to be the benefit of 'users at large' is if the neighborhood geek ran the service. He/She would already be keeping the security up for their own needs.. allowing others to VPN into a server and get out from their might be feasible *if* that person can handle the inevitable "but hellokitty.com doesn't work..fix it now!" type crap.
Likewise for the other main use, bypassing government controls.. I could perhaps envision something like a Ham Radio network, a bunch of volunteers organized to provide these services to others.