The key is that “humanity” doesn’t make decisions. Individuals do. The vast majority of individuals care more about themselves than about strangers, or about the statistical future masses. Public debate is mostly about signaling, so will be split between (a) and (b), depending on cultural/political affiliation. Actual behavior is generally selfish, so most will chose (a), maximizing their personal chances.
The key is that “humanity” doesn’t make decisions. Individuals do. The vast majority of individuals care more about themselves than about strangers, or about the statistical future masses. Public debate is mostly about signaling, so will be split between (a) and (b), depending on cultural/political affiliation. Actual behavior is generally selfish, so most will chose (a), maximizing their personal chances.