In what way are Musk's criticisms of the CA HSR plan FUD? Frankly, the HSR plan is a dud, and his criticisms are largely, if not entirely, valid. The cost is astronomically high, as a result of that the ticket costs will be greater than airfare. The route they've chosen also means that the journey will take far longer than it should. Would you actually consider taking a 2 hour 38 minute train trip from LA to SF at > $200 round-trip?

Even if Musk's Hyperloop proposal remains only a proposal, if nothing else it should give people serious pause about the existing plan, and hopefully force a revision of it. The route through Palmdale is utterly pointless, tacks on a dozen minutes to a trip that's already too long, and exists largely to satisfy NIMBYs and give fat checks to a bunch of property speculators. That particular element of the HSR plan reeks of cowardice, corruption and graft. Consider this as an alternative:

http://www.cahsrblog.com/2013/06/the-truth-about-tejon/

Musk's opposition to the existing plan is well reasoned and rational. Calling it FUD is itself a sort of FUD.

> In what way are Musk's criticisms of the CA HSR plan FUD?

No one is saying they were. The parent and grandparent are saying the Hyperloop announcement is FUD.

> if nothing else it should give people serious pause about the existing plan, and hopefully force a revision of it.

So, at the very least, the uncertainty and doubt parts of FUD?

Edit: s/fear/doubt