I agree, and I desperately want a Linux phone, but the really problem with Linux phones gaining traction is that is the developers are DEVELOPERS.
"I make $200,000 a year... how much should a good smartphone cost... how about $700? It's a bargain!"
I get that making hardware is expensive, but asking people to jump into something with a learning curve and real sacrifices at a premium price is just guaranteeing it stays niche - especially when asking an audience that by and large has to have an Android as a backup for some apps anyway.
And this is coming from someone with no fewer than 16 machines running various Linux distros in his house. You can't ask someone to spend that much on a secondary phone to play with until they get comfortable enough with it to switch completely. You just can't. It's barely working for the Linux OS, and that's free.