Any country that tries to ban private ownership of nuclear weapons would fall completely behind in all nuclear-weapon-related technologies. Should we therefore encourage the private ownership of nuclear weapons?

I entirely fail to see why this is a "fact".

Yeah we red-queens-raced ourselves into a position where now we have to have private cars, because if we don't we're screwed. Turned cheap 25-minute bike commutes into expensive 25-minute car commutes that can't safely or practically be biked, and shoved everything so far apart on account of giant parking lots and big highways cuttings straight through cities that the nearest bus stop is a half-mile away and that 25-minute car commute would take ninety minutes by bus, so now we have to have cars.

There's no quick fix at this point, it'd be a century-long project to undo the damage now, but a hypothetical world where we'd harnessed only the good parts of cars and not let them completely reshape the places we live down to the neighborhood level would sure be a lot nicer.

I'd argue that's /because/ we regulated aviation (and also some annoying physics limitations), so we never had the option of becoming fully dependent in the way lots of places have on cars.

Less than a century ago, so within living memory (albeit only just), literally nowhere on Earth was car dependent.