Bobby Fischer was also in a complete class of his own. He WON all 12 games in the US championship, something no one else has done, and he also had ridiculous winning streaks elsewhere.
Fischer, unlike the other great players, didn't prove that he could withstand the tide of time and outwit younger players with better/variable tactics. He continuously made excuses(often ridiculous) and tried every trick he could to avoid having to face a young and upcoming Karpov in '75.
Fischer was undoubtedly a good chess player for his timeframe('70-'73). But being a contender for 'greatest chess master'? Not by a loooong shot imo.
I think Fischer belongs on the list. At his peak, he was the best in the world by a mile. His demands regarding the Karpov match were unreasonable but FIDE still gave him most of what he wanted. I don't think he was afraid to play Karpov. Fischer would've won that match. Karpov was among the best of course but Fischer was in a class by himself. I think Fischer just didn't care. He had won the championship and he was satisfied with that. I think his position was that he would deign to defend his title - but only if he got everything he wanted. Keep in mind that this is the guy who walked out of the 1967 Interzonal with a record of 7 wins and 3 draws - because he disagreed with playing conditions and the schedule.
Bobby Fischer was also in a complete class of his own. He WON all 12 games in the US championship, something no one else has done, and he also had ridiculous winning streaks elsewhere.
There were 12 players. Fischer finished 11/11. That was impressive. And his back-to-back 6-0 matches against Taimanov and Larsen in the 1971 Candidates were remarkable.