Tbh I kinda get it. The below is my immediate thoughts but perhaps there’s another angle I’m not considering.
If you’re a professional player at that level then the sport is your life. You’ve probably been training since you were a child and you’ve completely dedicated yourself to it. Training almost every day, not doing things that other people get to do so as not to harm your performance, which probably affects your relationships.
In any sport where physicality is concerned, you have an expiry date. You will inevitably age out. It’s just a fact of life.
The Olympics is arguably the most culturally significant and important sporting event in human history so far, or at least one of them.
I can see why someone who has dedicated their life to their sport would make this decision to play in that event, even if they’ve already done it before, because they WILL age out of it sooner or later. And really, is one missing finger going to be that much of an impairment for the rest of his life? I’m guessing it’s not a thumb so… Probably not.
I think the decision is understandable and rational. I wouldn’t choose it myself, but I’m not a professional athlete who has dedicated their life to what they do.