Preserving the incompetent is rebellion against nature for the incompetent naturally perish. This is why it is inherently costly just like feathers of peacocks. Only the really strong can afford to preserve such morals without getting destroyed. Are we really that strong compared to AI or aliens that we should preserve the incompetent? Do we already rule over the universe? Nope? Then we can't afford to do that. Compassion towards the sufficiently incompetent is cruelty towards all human civilizations.