The question being debated is whether meat was a part of the diet of our ancestors. Whether it's justifiable is a seperate discussion and should not be brought into discussion. Facts don't depend on our moral opinion about them.

No, several questions are being debated. The comment you refer to also asked why eating should be considered evil. And the question of whether or not humans have evolved to eat meat, especially to eat meat anywhere near the levels that Westerners (and increasingly, Easterners) do today. Of course, it has been downmodded because it doesn't comport with the status quo.

The reason I asked for people to justify their eating of meat is that this is the first logical step in any of these debates. It is not up to me to tell you why your behavior is unjustified before you have even attempted to justify it yourself. Of course, whether or not humans evolved to eat is a separate question from whether or not it is moral to cause unnecessary suffering.

You can deride moral beliefs as mere "opinions," but moral propositions -- like all propositions -- contain ontological commitments. Those moral propositions that are founded upon false ontological propositions are bad moral propositions. Opinion doesn't come into that equation. Those who value their own suffering but do not value the suffering of others have breached logic and upheld falsehoods.

Voting me down for saying this:

"How about this: you prove that eating meat is justifiable? That would be something."

Whoever did it, you're realllly smart.

And again! I suppose some people don't believe they should have to justify themselves.

I just saw a bunch of comments basically screaming "YOU prove what YOU said! NO YUO!" back and forth, and downvoted all of you.

Wow. Thanks for reading, I guess.