I agree, though I would be even more prescriptive: when people hear of a new idea they should
first try to understand the upside (the value created if the idea takes off).
Then, think through obstacles/problems and put them in perspective with the upside. If the upside is deemed minor, it could be better to see if the core idea can be mutated into something more valuable before looking at obstacles/problems with the current idea.
(The split between "idea upside" and "obstacles/problems" that I've made is somewhat artificial -- you can say that a small upside is a problem -- but I think it's helpful.)
(EDIT: "idea" -> "idea upside")