It is not particularly convincing in the last part, the most relevant part: our own selfish interests in prioritizing people related to us over those not related, close to us over those far from us, and so on. It does a lot of handwaving around environmental interconnectedness but it doesn't add up to much of an argument if you don't fully buy the whole ecosystem thing, and if you do buy that, we should be paying more attention to bees than farm animals.