Although I agree with the author that political correctness is about mind control and censorship, and that it can be used for evil, bigoted uses, I disagree that it has not helped in making society more tolerant:

Because of political correctness, racists, sexists, homophobics and xenophobics are repressed from expressing their bigoted ideas. When these ideas are suppressed systematically, they tend to die, because less people are exposed to them.

However, it represses more than what is necessary, so it should be killed.