The article says:
If humans one day become extinct from a catastrophic collision, we would be the laughing stock of aliens in the galaxy, for having a large brain and a space program, yet we met the same fate as that pea-brained, space program-less dinosaurs that came before us.
More likely they would appreciate that we had more important stuff to get on with - and happened to be the victims of exceptionally bad luck.
No, I don't think that's how they'd view an unwillingness to set aside a miniscule fraction of our resources to prevent absolute destruction.
LessWrong is not big on discussion of non-AI existential risks. But Neil deGrasse Tyson notes killer asteroids not just as a generic problem, but as a specific one, naming Apophis as an imminent hazard.
So treat this as your exercise for today: what are the numbers, what is the risk, what are the costs, what actions are appropriate? Assume your answers need to work in the context of a society that's responded to the notion of anthropogenic climate change with almost nothing but blue vs. green politics.