Why did Bobby Fischer Quit Chess

#3
He did not play in 1969 when he was analysing for his book "My 60 Memorable Games"
He did not play in the Nice Olympiad as organisers rejected his demands e.g. a separate building for him as World Champion, his opponent, and the public.
He did not play against Karpov because FIDE rejected his demands e.g. play for 10 wins, draws not counting and Fischer retaining his title in case of 9-9.
He did play a revanche match against Spassky in 1992 though the USA had declared it illegal to play in Yugoslavia because of sanctions and Fischer exiled himself by playing.

Fischer was already becoming rather unstable by the late 60s. He was showing evidence of both paranoia and delusional thought patterns. By the mid-70s It had pretty well taken over his thinking.
Read the transcript of his radio interview with Radio Bomba, Baguio.
I feel that his failure to defend his title in 1975 was just another symptom of his deteriorating mental health.
#4
He was willing to play both in the Nice olympiad and against Karpov, but his demands were rejected.
He almost did not play against Spassky in 1972 and he had booked 3 flights home after game 1.
He refused to play at the Lugano 1968 olympiad, as his demands regarding tables, chairs, chess sets and lighting were rejected.
He refused to play the 1970 US National Championship which counted as Zonal Tournaments in the World Championship cycle because they rejected his financial demands.
He withdrew from the Sousse 1967 Interzonal while leading because of some dispute.
He refused to ever play a Candidates' Tournament again after he accused the players of the Soviet Union to collude at the Curaçao Candidates' Tournament.
He was a man of principles.


The kid started off a bit off-kilter, and grew worse with age. Though one of the best, if not the best chess player ever (depending on who you ask), he was a lousy human being who was always on the precipice, but at some point went full-on crazy.

You can hear from Fischer himself - too much opening theory ruined the creativity of the game:
https://www.youtube.com/watch?v=P349BdHUxlc&t=3s
tada...
Trying to answer, when there are videos of Fischer on Youtube, is beyond me...

The opening theory was way more advanced in 1992 so his excuses for running away from Karpov in 1975 are void.

Just out of curiosity