I have no idea where you got those suggestions. Neither one is accurate about my beliefs: I don't go around using the concept of virtue when I talk about ethics, and I only think bad things can be also unethical when they are the result of deliberate or negligent actions/inactions by a person. I think ethics is about the behavior of persons, not the behavior of lions or the edibility of antelopes.

I get my opinions about who should be a vegetarian by the following logic:

I would not up and kill a cow/chicken/guinea pig/cat/whatever for no reason. It seems to me that it would be wrong to go around killing animals (or, for that matter, smashing vases or setting books on fire or committing any act of destruction) for no reason.

It seems that there are some reasons where it would be quite okay to kill an animal (or smash a vase or set a book on fire). If I were starving (if I needed a shard of ceramic to cut some wrongly convicted-of-witchcraft person free from a stake/if I were otherwise going to freeze to death) then I would kill and eat a cow (smash a vase/set a book on fire).

So somewhere in the space of reason-having, between "no reason" and "otherwise a person will die", there must be a threshold of adequacy sufficient to kill an animal (or do any other destructive thing). For the death-for-food of non-personhood-having animals, I draw that line at the excellent quality of life of whoever might eat them. I can have an excellent quality of life and eat only occasional fish. My friend who gets sick when she doesn't eat enough meat can't. So she needn't be a vegetarian, but I should.

Not to defend dishonest interpretations of science here, but... "heritability" sounds like a unfortunate choice of word for the concept described. It invites inadvertent misrepresentations.

I'm reminded of an old OB comment by Anatoly Vorobey that made the reasonable point that Kolmogorov complexity captures the human notion of "complexity" very lousily at best. (WTF, the whole universe is less complex than one planet within it?) So too it seems with "heritability". People clearly want a number that would describe "how much the over-all level of the trait is under genetic control, and... how much the trait can change under environmental interventions" - why can't the biologists just give them that?

Bacon is not made from cows.

Even if bacon were made from cows, it is not clear that a reduced cow population would hurt any existing cows.

All moral codes drill down to a rocky core of "ick," though. Suppose A says, "Well it's clearly wrong." And C says, "No, it's not. Make your case." The case is made when A says, "B inevitably leads to D. Does D make you feel icky?" and C says, "It does."

It's true that people in the past had a lot of icky feelings we don't have today. We also have a lot of icky feelings they didn't have. Given that, I would like to see a follow-up article written about, under this framework, how many more letters of the alphabet have to agree with A before A gets to punish C for making him feel icky, depending on the number of letters in agreement, how severe the ick, that kind of thing.

I think it is unethical for humans who can enjoy an excellent quality of life as vegetarians to eat other animals. I have a friend who becomes seriously ill if she tries to do without eating a mammal or a bird for more than, at best, one meal. She should not be a vegetarian. People with serious allergies to many vegetarian protein sources, people who are living in economically marginal situations and have to take whatever they can get, and maybe even the people who seem to worship bacon as nigh unto a god should not be vegetarians. I think more people should be vegetarians than are. I think all people should consider the possibility with some serious thought, because there are more ways to be a vegetarian all the time.

I suggest legumes, soy products, seitan, mycoprotein, dairy, eggs, the least formerly-intelligent meat you can find if any, and lots and lots of plant-based dietary variety.

Is the problem that English is not your first language?

Good meaning 'useful for a particular purpose', bad is its negation. Whether the middle is excluded might be a matter of contention.

So does that mean vegetarians are ok with eating animals that were treated very humanly or that died of natural causes? Could a vegetarian here explain?

I'm a pescetarian, but let's assume I count. I wouldn't eat those animals because non-fish meat no longer resembles food to me; because if I resumed eating meat of any kind, it would be more difficult to resist meat of inappropriate provenance; and because humanely-treated meat is hard to come by (and still has to be slaughtered) and naturally-dead meat is of suspect quality.

In case there are no vegetarians on this site, how are we driving away or failing to attract vegetarians?

For an idea of how many vegetarians we have, check out this poll.

What's 'bad'?

It seems like vegeterianism would lead to cow extinction or very close to it.

It would, but that's an entirely separate issue from animal cruelty.