It seems from my perspective that we are talking past each other and that your responses are no longer tracking the original point. I don't personally think that deserves upvotes, but others obviously differ.

Your original claim was that:

Said literature gives advice, reasoning and conclusions that is epistemically, instrumentally and normatively bad.

Now given that game theory is not making any normative claims, it can't be saying things which are normatively bad. Similarly since game theory does not say that you should either go out and act like a game-theory-rational agent or that you should act as if others will do so, it can't be saying anything instrumentally bad either.

I just don't see how it could even be possible for game theory to do what you claim it does. That would be like stating that a document describing the rules of poker was instrumentally and normatively bad because it encouraged wasteful, zero-sum gaming. It would be mistaking description for prescription.

We have already agreed, I think, that there is nothing epistemically bad about game theory taken as it is.

Everything below responds to the off-track discussion above and can be safely ignored by posters not specifically interested in that digression.

In game theory each player's payoff matrix is their own. Notice that Codependent Romeo does not care where Codependent Juliet ends up in her payoff matrix. If Codependent Romeo was altruistic in the sense of wanting to maximise Juliet's satisfaction with her payoff, he'd be keeping silent. Because Codependent Romeo is game-theory-rational, he's indifferent to Codependent Juliet's satisfaction with her outcome and only cares about maximising his personal payoff.

The standard assumption in a game-theoretic analysis is that a poker player wants money, a chess player wants to win chess games and so on, and that they are indifferent to their opponent(s) opinion about the outcome, just as Codependent Romeo is maximising his own payoff matrix and is indifferent to Codependent Juliet's.

That is what we attempt to convey when we tell people that game-theory-rational players are neither benevolent nor malevolent. Even if you incorporate something you want to call "altruism" into their preference order, they still don't care directly about where anyone else ends up in those other peoples' preference orders.