Personally, and from my experience, those college educated women are married to much higher income earning men and just see a big pay day relative to the non-college people. I really don't think its cheating causing the divorces. According to this study, the average age of divorce is around 30 and according to your study only around 1 in 8 people have cheated by that age, and significantly fewer than that caught.
I think the 50/50 ratio among non-college grad and a chunk of the 90/10 college grad are caused by 1) money issues by one or both spouses 2) cheating 3) one or both spouses letting themselves go physical. The rest, IMO, is largely about someone, usually women, seeing a big payday.
I think you are ignoring substance abuse and domestic violence in those numbers both of which are higher for males and are no respecters of income.
Men do not want to hear this, but they have a higher rate of risk taking behavior, higher rates of violence, murder rates (as both perpetrators and victims) mental illness, and most other negative social or health risks. All of which impact their ability to sustain a marriage.
But the real dirty secret is that overall 50% divorce rates are driven by a hard core group of serial marriers/divorcers who are chronic failures at marriage, yet continue to remarry. This group is mostly made up of not losers, but grifters, narcissists and sociopaths of both genders who never seem to marry each other but burn a wide swath through the rest of the population all while squealing and blame shifting.