“Not sure i understand why meat eaters get so picky over what animals they will and wont eat“
It’s because people like to have confidence in the trustworthiness of food producers. Things like BSE (and, resultingly, CJD with its associated deaths) happen because meat producers are under pressure by people like Tesco to produce meat at very low cost. This results in bad practices which can be a severe health issue.
The point is that regulation exists to prevent low-cost meat from being a health issue in the same way that it was with BSE and suchlike. Not everyone can afford to shop at the farmers’ market every Sunday; in fact most people can’t.
I believe there was also pork found in the burgers, and clearly that’s also an issue for people whose religion prohibits them to eat it.
Personally, while I’d happily eat horse or any red meat I can think of, I’d be pissed off if I found I’d been fraudulently sold meat such as battery chickens or crated veal. Equally, of course, I’d be pissed off if I bought beef that had been fed on sheep, because we’ve legislated to stop precisely that.
So there are several very good reasons why people find it unacceptable to buy beef and get horse and pig, and even if you’re fine with eating any old mammal, the real issue is that the trustworthiness of Tesco and its supply chain has been brought sharply into question. They don’t know where their meat has come from, they don’t know how it’s been produced, and neither do you.
Taking a broad view of eligible species for your plate isn’t remotely the same as not giving a toss about what you stick in your mouth.