I'm pretty sure the main objection isn't how much money they took, it's that they've shown very little evidence of actually being able to back up their claims. How much money they were able to raise just makes it look more egregious.
If you want to see a lightfield display you can just visit Display Week (http://www.displayweek.org/). Once you see one in person your doubts will be put to rest.
Is there an alternative to agile that's available out there?
It doesn't mean releasing things before they are ready. Agile is about potentially shippable increments and customer collaboration. Again this doesn't mean testing in production.
While the manifesto was written for software, with minor changes it can applied to most industries. Even with hardware, agile principles can be used to iterate on design, not necessarily physical production.
http://agilemanifesto.org/principles.html