> how to build a culture willing to maintain life support systems for generations

Do we not already have a culture willing to maintain culinary water systems, sewage, the electrical grid, etc? Sure it's not as bad if one of those goes offline sad with life support but we pretty well can and do take for granted that those things are always there. And pretty rarely are any of these offline everywhere in a given area. There's plenty of redundancy.

Speaking of which, no doubt some thought will be needed for non Earthly natural disasters.