--
Let me, as a chess player, say that I was much less surprised by the resistance the World put up against Kasparov:
A) Kasparov is indeed considered the greatest player by most and the reason for his strength when playing ‘over the board’ (OTB, as it is termed) was threefold: 1) he prepared more and better than anyone else 2) his calculating powers OTB were quite magnificent and 3) his understanding of dynamic chess was ahead of his time. Now when using the format of the Kasparov vs the World game these advantages largely (not completely) disappear: 1) everyone can consult books (in particular about openings), 2) everyone can move the pieces around on the board instead of inside their heads 3) the game was not a messy game Kasparov used to excel in but quickly went into a middle game with endgame features.
B) Kasparov may be “much better” than other GMs and than Krush in particular, but this difference in strength should be qualified. The difference between me and most tournament players in the US player is much larger than that between Kasparov and Krush! The median rating of US chess players [those who play tournaments and actually do have an official rating] is somewhere around 1000-1100, mine is more than 1100 points higher. Kasparov is “only” about 300-400 points above Krush (and like 150 points above Khalifman).
C) There is a good comparison with correspondence chess here: this is where people play by email, for instance, (it used to be by snail mail). I just started playing this myself and the tempo in most games is about 1 move per day. Now I play several people whose OTB ratings are way below mine, indeed a 1000 points below mine. But I don’t have an easy time beating those players in correspondence chess. A difference of 1000 points implies I can beat them, when playing OTB, literally blindfolded (just seeing the board in my head). But in correspondence chess it’s much much harder. They can use opening books and look up how grandmasters have played in the position we happen to have on the board.