Ethanol has a propensity to suck up ambient moisture and is more demanding of rubbers and happily attacks aluminum.

In an age of natural rubber components, poorly sealed fuel systems with steel tanks and aluminum carburetors pretty much anything other than ethanol is the "right choice".

And once they ruled out ethanol they settled on lead because it was cheap/profitable. Obviously they chose wrong, they should've picked something more expensive but less terrible.

These weren't cartoon villains with monocles twirling their mustaches. They were normal humans making pragmatic decisions based on the constraints they faced. Without knowing the details people cannot understand what future similar fact patterns may look like.

That said, it should be no surprise to anyone that nobody wants to talk about "well we don't know how bad the harm of leaded exhaust is, we know it's not good, but it's diffuse and undefined so we'll round it to zero/negligible" type decision making, for that sort of unknown rounds to zero logic underpins in whole or part all manner of modern policy discourse.

The kinda are/were

https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.