There is an odd mythology growing around the alleged increased "difficulty" of Augusta National for the Masters, perhaps as a lingering result of: a) the changes made in the mid-2000s, that immediately afterwards led to some low-scoring tournaments; and b) Tiger not being the player he once was, when he won 4 Masters with a score never anything worse than -12.
In the last four years, the winning score at the Masters has
averaged -13; only once in the history of the tournament (well, twice: the '94-97 period, and the '95-98 period, the point being both of those included Tiger's record -18 in '97) has that been bettered, and only once equaled, in the period between 1975 and 1978, when the four winners were Nicklaus, Floyd, Watson and Player, only four of the six or seven best players of their generation.
Much of people's view of low scoring at the Masters, I'm convinced, is associated with the period from around 1990 (Faldo at -10) though Tiger's 1997 win, when the winning score was in double digits all but one year (Olazabal, '94, -9) and -- more importantly -- Augusta still played at under 7,000 yards despite exponential betterment in club and ball technology (of the sort that allowed Tiger to hit 9-irons into par 5s in '97).
I'm of the view the folks who run Augusta have the balance pretty well figure out; last year saw 29 eagles in the tournament, not that far off the all-time record of 37 set in 1991.