It didn't. What we are experiencing is an effort by the Marxists in our midst to convince us that "tolerance" is paramount.
This is part and parcel of their program to replace our society which is based on a balance of individual merit AND community with a system-based solely on community (i.e., collectivism with no room for individual merit).
A system based ONLY on community is no more possible than a system based only on individual merit.
A culture must have both, just as ancient tribes had great hunters and communities, with each supporting the other.
As part of going from a self-restraint based society to a tolerance based one, it seems a person's character is judged on how much a person tolerates others, rather than on how well they refrain from behaviors that others have to tolerate. And people in contemporary society reach such a level of giddiness if they can view themselves tolerant that it's like a drug in their system.