Well, there may be no objective grounds for valuing a groundhog more than one of the Joad brothers; but from a human point of view, the angles seem to support the sense that human survival depends on human survival -- we survive as well as all others. When an organism cuts across our bows by chewing up our vegetables, he becomes fair game, valuable or not.
The computations about survival are not just one-unit-organism. We also want out families to be there tomorrow, and our groups, our races and towns, our species overall. That's why contemplating "right" action is complex and so debatable. It hinges on opinions about probable outcomes, and opinions -- well, we know what tey're like.
As for the survival potential of cockroaches, they are well adopted to bring about cockroacvh survival.
Human survival is a lot more complex, I believe, and a lot richer in shades of value. So even thugh it may be a much more difficult game, I am glad to be playing it instead of the cockroach version.