Chess doesn't require understanding human goals if you're an AI, just running through the space of winning moves that your training encountered. An AI doesn't think "ah, rook to E4, knowing Kasparov, he will then castle and I can do X". It'll just go "lol I encountered 3 486 864 games with this particular board pattern and 49 652 lead to a victory lemme pick one for the lulz".

Chess is really just about searching through as much of the space as possible, and you can take a few seconds. And believe me, there's a whole lot more stupid behaviours you can encounter on the road while you have to react in less than a second.