Don't table tennis players learn to predict how the ball will act based on their opponents movements? Seems like if they aren't able to do that with a robot opponent (who doesn't look or behave like a human) then they wouldn't be able to play at their best.
That's not true. If you read the article Kojima even said he wanted to make a zombie style MGS game and pitched a zombie game based on nano bots before the development of MGSV.