> the likelihood of failure is high but the expected value is positive

Except when the new technology was proposed and marketed by a loony, of course.

I sense some notes of disagreement with calling the Tesla CEO "a loony"

The likelihood of failure is 100% when the technology is as ridiculous as the hyperloop. It's just yet more gadgetbahn, except it's transparently worse.

* 10% of the optimists make money

The optimists get more than one at bat.

And pessimists don’t?

I think the implication is that pessimists don’t try.

Your assumption is only true if trying never has a negative downside.

I don’t see how that follows.

My take on the GP meaning: Failure diminishes trust from investors.

If you got 1 milliion from investors, and you blew it/wasted it/burned it. It will be harder to get the million for the 2nd idea.

Talk about a false dichotomy there. No person is fully a pessimist or optimist. Framing it in terms like this just serves to stifle actual discussion. A nice soundbite from someone who happened to be optimistic about the right thing.