Yes, this seems plausible to me. What I was saying is that that would be a reason why the EV of arbitrary actions might often be negative, rather than directly being a reason why people will overestimate the EV of arbitrary actions. The claim “People should take the pure EV perspective” is consistent with the claim “A large portion of actions have negative EV and shouldn’t be taken”. This is because taking the pure EV perspective would involve assessing both the benefits and risks (which could include adjusting for the chance of many unknown unknowns that would lead to harm), and then deciding against doing actions that appear negative.
As far as the third point goes for most non-anti-fragile systems the effects of unknown unknowns are more likely to be harmful then benefitial.
Yes, this seems plausible to me. What I was saying is that that would be a reason why the EV of arbitrary actions might often be negative, rather than directly being a reason why people will overestimate the EV of arbitrary actions. The claim “People should take the pure EV perspective” is consistent with the claim “A large portion of actions have negative EV and shouldn’t be taken”. This is because taking the pure EV perspective would involve assessing both the benefits and risks (which could include adjusting for the chance of many unknown unknowns that would lead to harm), and then deciding against doing actions that appear negative.