I’m not sure the assumption of many is that women are the fault behind divorces. However, I have heard people say that, and I have also heard people say that it is the men’s fault. Both statements are ridiculous. The factors that are responsible for divorce are many, and any pronouncing of a single issue or a particular direction is baseless and unprovable.
It is a fundamental human frailty to generalize. It makes life so much simpler to understand. But making these statements has never impacted the reality on the ground.
It also deserves to be added that anyone on the outside of the marital conflict cannot possibly know all the issues that are the dividers in a relationship. So even if you know of a particular couple who are getting divorced or already did, it is worse than presumptuous to believe you know anything about what really happened.