I don’t think that claim is wrong.
Then we disagree.
I think that’s fully dependent upon the DM to make that shift but the book is making it very clear that if you want to kill orcs, they are the bad guys. Just the same way blowing up a whole Death Star full of stormtroopers is fine because they’re the bad guys - don’t dwell on the morality of it.
While I think the book is making it very clear that most orcs, due to their culture, do hostile things against other cultures and are warlike. Those other cultures, naturally, will defend themselves or flee.
And yet Finn shows use not all stormtroopers are bad, but because of how they are raised/trained--just like orcs in that fashion. Was it ok to blow up all those stormtroopers? No, but it was war and both willing and unwilling troops sadly die in war. It is regrettable and should never IMO be "fine".
So, the claim that orcs are inherently evil and can be slaughtered without remorse is wrong. When were talking about good and evil, morality is part of that conversation. Killing a race of peoples (or species) simply because you think they are evil or whatever and doing so without remorse is, itself, evil IMO. I don't care to foster that attitude any further than others already have. Saying it is acceptable for others to claim that falls into the realm of "All that needs for evil to prosper is for good to do nothing" (or whatever the quote is...).
Can I refer you to the concept of the "dog whistle"? It's a concept in public speaking where you don't overtly say what you mean, but the language is known by those who are familiar with it's second meaning. Politicians use it all the time when they want you know who is really responsible for a certain problem without saying the quiet part out loud.
Yes, I am familiar with such concepts, however, in this case the author explicitly states orcs are not inherently evil, like gnolls (for instance).
You can be hot-tempered, violent, etc. without being evil. You can glory in struggle and contest and such without being evil. Orcs combat against those who stand up to them or they deem worthy foes because they view combat as glorious and victory over ones enemies as a measure of status. If peoples flees before the might of the horde then they might laugh at the weak and cowardly as they run away because they view them as inferior. Certainly, this sort of culture lends itself to creating evil individuals, who relish in the kill itself.
For example, nobody needed to explain why runaway slaves should be lynched. There was no law on the books, no passage in the Bible, that said that. But the people knew that certain laws gave them the ability (or at least excused it) and the Bible could justify it by selective reading of certain passages. You don't need me to say four when you can do 2+2 in your head.
The people who accept that without explaination, a law, a religious passage, etc. do so because they:
1. believed it was right so did it themselves, whether because they enjoyed it or felt it served as warning to other runaways.
2. were never shown another way. Others around them lynched, so they lynched.
3. knew it was wrong but where too scared to stand up against the mob.
4. knew it was wrong and stood up against it to their own peril.
5. other reasons I can't think of at the moment.
Which is what the problem is here. The language surrounding orcs are dog whistles. Specifically, they are sometimes the EXACT dog whistles that were used in the real world against minorities. Which is the problem. It triggers the same emotional reaction in us. And the words we use to justify slaughtering the orcs in the Caves of Chaos mirror the words a white gang used to justify lynchings.
No, the problem is people reading something one way and not seeing the possibility it can be interpreted another way. For those individuals I imagine the language could be problemetic--"hitting too close to home" as it were.
Nothing in the language of the text in Volo's bothers me for a couple reasons:
1. it is a game and I understand that.
2. it is not my culture and I can view another culture objectively. I might not personally agree with some aspects of that culture, but who am I to judge?
Many Americans enjoy American football (myself being one of them). I enjoy the contest of strategy, will, physical prowess, training, etc. and everything that those games and athletes exhibit. Yet I know there are many Americans who find football "barbaric and savage", etc., but even though I can see their point of view, I can appreciate mine.
As for the Caves of Chaos, sure, things were different 40 years ago. And things were different 40 years before that, and things will likely be different 40 years from now... The difference is if you really read the Volo's text and do so without the prejudice of prior years, it is a different experience and does not support the claim to slaughter orcs without remorse. That is precisely the sort of thinking I am arguing against.