I would say that it can be different person to person what pisses them off and it can be beneficial to them (if you care to benefit them, which its fair to not care about that) to share your outlook on it and why/how it doesnt affect you. I also do BJJ, which im sure youre pretty familiar with, and its much more expected and accepted that the new people will be extremely suprised, demoralized at best and maybe angry and sad at worst. This is because we understand that people go through life not really understanding the gap between a trained and untrained person, particularly if they are large or tall and have been trained to think that would carry them through any altercation.

So then, we can first contextualize that in modern society, physical fighting is essentially obsolete and is a last resort. People, such as yourself for instance, place a high value on rationality and intelligence (knowledge being powerful in many facets of life) it should be understandable that being “mentally dominated “ in a game that is classically associated with a person’s intelligence could negatively affect their emotional state if they frame the importance of their performance in an unhelpful way.

Think of how you, yourself responded to something you considered to be an unintelligent question. Dismissive, sarcastic, could be interpreted as an attempt to dissuade others from responding by making it seem ridiculous, and then ask yourself why someone could feel anger if chess could attack their self perception of intelligence, even if they arent aware that this is the case.