Larry Parr wrote (2003-09-21 21:34:41 PST):

It's obvious [Fischer's 1974] conditions
were unfair. But not when compared to what
FIDE routinely granted Soviet world champions.

_
Is there any reason to doubt that Fischer
could have had (if he wanted) the same
conditions that Spassky had in 1972 and
Petrosian had in 1966 and 1969?

In case anyone is new to this discussion,
Fischer wanted a rule that would have
required a challenger to finish two
or more points ahead of Fischer in
order to cause Fischer to lose the
title.

"Bobby Fischer had sent in a number of demands ... Some
of these were conceded ... But two demands were rejected.
... Numerous telegrams had been sent to the Congress by
Fischer via his spokesman, Fred Cramer. The last one said
that, in the light of FIDE's decisions, he was resigning his
FIDE world-championship title. ... Another attempt was
made to bring the FIDE and Fischer into complete accord,
when Colonel Edmondson (U.S. Chess Federation) asked
for the summoning of an extraordinary meeting of the FIDE
Congress. There being a sufficient number of countries in
agreement, it duly assembled at Bergen-aan-Zee in the
Netherlands from 18 to 20 March, 1975. It was an
extraordinary congress in every sense of the word, and
eventually, after much heated discussion, one of Fischer's
demands was conceded: the match was to have a limitless
number of games. But Fischer's other demand - that a
draw be declared when the situation reached nine to nine
- was rejected by a majority of three. Fischer's words on
hearing this were, 'It's all over then.' No match took place.
Fischer ignored the request to say by 2 April whether or not
he would play, and Karpov became the new world champion"
- Golombek (1976)

Incidently, in 1978, 1981, and 1984, FIDE did
decide to hold world championships where there
was "a limitless number of games", but there
was no rule that required the challenger to
finish two or more points ahead of the champion
in order to cause the champion to lose the title.
On the other hand, there WAS the rematch rule
that would have required a new champion to
play another championship match with the defeated
champion after one year.