True, but I think it was focusing on things under the control of the producers of this product... of course, I suppose spending more on lobbying to try to reduce subsidies or tax externalities for meat is under their control. It seems like a kind of unwinnable battle though doesn't it?

The OP does touch on the subsidies by suggesting the producers rely more on soy and corn, which are heavily subsidized, and as are used as animal feed and thereby constitute a pretty major source of the meat subsidy. While not about externalities, I think they could have pointed out the reasons corn and soy are so cheap compared to other plant sources are in large part a result of government policy.