Wow, guys. I would have expected more of the less wrong crowd.
You emotionally dislike the fact that voting is irrational, so you’ve downvoted this post, but you haven’t even attempted to reason with me.
If I’m wrong, tell me why. Don’t just have an emotional reaction.
The case you described, where the cancer cell resulted in the death of the individual human, could equally well be described as kin selection. An individual that hurt its close genetic relatives- and actually actively kills them- also hurts its individual reproductive success.
The argument against group selection is an argument against its usefulness as a concept. Where group selection works, it is mathematically indistinguishable from kin selection, so you might as well use kin selection as your conceptual model. Additionally, it can be confusing for people who don’t understand the circumstances where it definitely cannot work, which is any case where the individuals are not closely related.