I think a lot of the time people see stupidity in differences of values and limited visibility of the context the decision was made. I think this is why so many people think so many people are stupid. 'Stupid people' make choices that the observer sees as having 'poor results'.

Like when a lane ends on the highway:

-- People are stupid (and selfish) for not letting cars in when their lane ends (dangerous)

--People are stupid (and selfish) for waiting until the last minute to move over (dangerous)

-- People are stupid for moving over well before their lane ends (missed opportunity to get ahead)

-- people are stupid for being in either of those lanes that merge when there is a third lane that doesn't merge.... (short sighted and dangerous) (no I won't let them in! They should have thought ahead)

--People are stupid (and selfish) for driving cars (dangerous, climate change)

--People are stupid for thinking it's reasonable to live without a car (missed opportunity to get ahead)

Not me though, I consider everything from all sides all the time no matter what. Anyone that doesn't invest their time like this to make decisions is... stupid. (/s)