Your point 1 completely disregards duplicity or the prospect of bait-and-switch.
A con that is pitched out the gate as a con does not gather suckers with anything near the success rate of a rationalizable technology. It's a well known fact that "intelligent" marks can be easier to grift if they can be sold that their "getting grifted" is "getting ahead of the idiots on the next big thing". They practically fill in all the blanks for you with their own imagination.
The ones who take the time to sit down and actually think about how the value proposition is backed, and look at "what a system does, rather than what it's pitched to do" are far more difficult to tap.
Frankly, I assume everything starts as a grift, and only becomes not one through the stakes becoming so large for the "Emperor's New Clothes" moment that no one wants to talk about it.
I'd think a board full of VC's would be somewhat more aware of this. Or is this one of the parts no one talks about because it gets the marks nervous?