the real reason is that fischer wants his own condition to be used in the match.... fide that time did not accept such condition which is fair for both players according to fischer and I also think is a good condition....
But I dont understand fide they did not accept fischers condition for the 1975 match but later in 1978 they used the condition only its the first player to win 6 will be the winner or the champ... this happened between anatoly karpov and korchnoi in Baguio city Philippines. heres the site for proof:
http://www.chessgames.com/perl/chess.pl?tid=54641
Chess players the world over will find something almost comfortingly appropriate in the timing of Bobby Fischer's death. He was 64 years old; there are, of course, 64 squares on the chess board.
That number lies at the heart of the mysteries of the game Fischer dominated as few others have ever done. Combined with the functions of the eight pieces and eight pawns allotted to each side, it generates a fearsome problem that no human mind – or silicon one – can encompass. The number of possible chess games that could occur is overwhelmingly larger than the number of atoms thought to be contained in the universe.
The grandmaster described in Nabokov's great novel on chess, The Luzhin Defense, is driven mad when he suddenly sees "the full horror and abysmal depths of chess". Non-chess players tend to argue that Fischer was driven crazy for similar reasons. We chessplayers like to think we know better: we say that it was only chess which kept him sane. It was after Fischer gave up playing – and his career effectively ended at the age of 29 in 1972, after he beat Boris Spassky to become world chess champion – that his psychoses reduced him to little more than a ranting tramp.
What we find difficult to encompass is that a man of such ugliness of character – his pathological anti-Semitism was expressed in language that Goebbels would have thought crude – could also have created chess games of breathtaking beauty. The first Soviet world champion, Mikhail Botvinnik, once observed that "chess is an art which illustrates the beauty of logic". On that analogy, Fischer was the Mozart of chess: his best games have a purity and simplicity of expression that no other player could emulate. Yet – and here is where chess is dramatically different from mere artistic self-expression – Fischer was also the most ferocious "killer" of the 64 squares.
Chess is unusual, perhaps even unique as a sport, in that the combatants can at any stage agree a game drawn. When Fischer arrived on the scene, the game was almost dying of what became known as "the grandmaster draw". The top players would regularly agree to "split the point" with each other, often to the irritation of spectators, who wanted to see blood.
Fischer gave the fans blood, buckets of the stuff. He would never agree draws – even in apparently prospectless positions against very strong grandmasters. For Fischer, every game was a fight to the death – and this searing, relentless will to win intimidated even the greatest opponents into making blunders they would never have made against anyone else.
It was this ferocious sporting attitude – as much as the fact that he was an American loner up against apparently mass-produced Soviet grandmasters – that encouraged a whole generation of young chessplayers in this country. I know: I was one of them.
That is why we felt such a sense of betrayal at the way in which Fischer – without any indication of regret – gave up the game that he had made us love. No one really knows why he abdicated – by refusing in 1975 to play his first official challenger, the lethally pragmatic Anatoly Karpov. (Ostensibly it was because the Russians refused to accept every single one of Fischer's match conditions. There were 64 of them, of course.)
Karpov himself once offered an explanation: "I don't want to claim that Fischer was afraid of me. Most probably he was afraid of himself. He believed that the world champion has no right to make mistakes. But with such a belief you can't play chess, because you can't avoid mistakes."
In other words, no matter how good you are, the 64 squares are too much for the human mind – any human mind – to control. They defeated Bobby Fischer, as they defeat us all.