Morality in the game

If the rules are a general assumption then that is understandable (obviously). But what if these moral rules are a matter of dispute between two groups, meaning that only some of the players use them. In a way that in my personal opinion it is better for everyone to play without these rules, because they really have a negative impact – and this is the dominant opinion among the players there with a medium-high rating and above – on the game, but I happened to find myself in a game with a noble moralist who influenced me with his good morals out of his opinion that this is how the game should be played, and he of course expects reciprocity from me.
Is it required on my part to behave with him according to his rules? But I am not interested in these rules.
Should I not take the help he offers me in the first place? To me, this no longer seems reasonable. I can not always control this help. For example, the most basic type of help is simply not to attack me. If I see that the aforementioned noble moralist doesn't attack me when he has the chance, then I'm likely to invest less in defenses against him, and this is a very significant help. Expecting me to ignore my assumption that he won't attack me in the game seems very strange to me. And in general, playing in a non-optimal way from the game's perspective is also bad (because there is no predictability).
By the way, what is true is that many times when I saw that he was being excessively moralistic, I wrote to him in the (public) chat clearly not to trust me because "I don't promise not to attack him." The problem is that if it's a real donkey, then such a clarification for some reason causes him to attack me obsessively (which almost always causes us both to go down together). And besides, in most games the players are anonymous, so the chat is turned off.

[My decision at the time was to play solely to win without any other consideration, unless it had no impact on the victory. But still, during the execution of a particularly chilling and lucrative betrayal towards someone who did me a favor, I would experience some kind of back spasm, and sometimes I would avoid it and even return the favor and maybe even take a slight risk to return the favor (which is very frustrating for the other players if they do not hold this morality, by the way, because a favor to one always means a bad thing to another). And it turns out that they lost because of moral principles and not because of pure playing ability. If, for example, there are three of us left, and I am “loyal” to someone who did me a favor, then the third one almost certainly loses. At some point, morality really degenerates the game. Games without morality, that is, games in which the alliance system changes almost every few turns depending solely on the current situation and without regard to the past, meaning that each player tries to maximize only his own chance of victory, are undoubtedly much more interesting and sophisticated games, and only with such players is it fun (for me) to play. As far as I am concerned, adding external *constraints* to it is really poisoning Wells. By the way, the link was broken with a space (not that anyone cares) and here is the correct one: https://www.chess.com/clubs/forum/view/is-it-a-game-without-morals ).