When Montag is trying to understand how Mildred could have turned him in, and trying to figure out a way to save his books, Chief Beatty taunts him:
"This is happening to me," said Montag.
"What a dreadful surprise," said Beatty. "For everyone nowadays knows, absolutely is certain, that nothing will ever happen to me. Others die, I go on. There are no consequences and no responsibilities. Except that there are."
(Bradbury, Fahrenheit 451, Google Books)
The parallel with modern society is that the loss of personal responsibility, and the idea that there are no consequences, creates an entitled society. When tolerance enables one to make bad decisions and suffer no adverse consequences, the lesson learned is that one's personal action is always correct, and if people oppose you, it is because they are inferior. There are dozens of examples in modern society of people making bad decisions and being rescued from the consequences; the example that everyone knows is the bank bailouts, where bad decisions were rewarded with money to save the institution. When people are not allowed to fail, and when failure is not allowed to have adverse consequences, the concept of personal responsibility begins to vanish, until people think that any course they take in life should be subsidized by others, regardless of its objective value. When people take responsibility for their actions -- "I did [this] and I accept the consequences" -- it leads to a stronger society.