Hmmm I think it's a bit of a stretch to say mesh networking hasn't really worked out. It just hasn't spread far enough yet.

Have you heard of CJDNS[1]? or BATMAN[2]?

Hyperboria[3] is multiple sizeable deployments of CJDNS. Maybe you heard of Freifunk[4] in Germany, with over 40k access points so far.

[1] https://github.com/cjdelisle/cjdns

[2] https://en.wikipedia.org/wiki/B.A.T.M.A.N.

[3] http://hyperboria.net/

[4] https://en.wikipedia.org/wiki/Freifunk