[selfie]

Build it and they'll come? At least one end has to be somewhere people want to be, right? A line from London into the countryside makes sense. You can live in the countryside and work in London. A line from nowhere to nowhere is a chicken/egg problem. Now if one end is an Airport and another is a new community who will have jobs at the airport, that might work.

[microtherion]

I don't know whether people want to be in Merced or Bakersfield, but de facto, plenty of them are there.

[jhbadger]

They both are university towns (UC Merced and Cal State Bakersfield); given that academics are generally positively inclined towards public transit a line could encourage collaborations, I suppose.