Consumers don't care about technology ideology. Native vs web, NOBODY CARES!
Consumers want their apps. They want to play games. They want instagram. They want beautiful hardware and lots of accessories.
The only place in major markets where a Firefox OS stands a chance is low cost prepaid like Virgin Mobile USA, Straight Talk, etc. but there are enough good android options and even iPhone now, that it might be too late.
Maybe it could take off in some other countries, but I don't see Firefox OS taking off like the original Firefox did.