Yes, it's been said - it's an avoidance tactic, they don't like feeling guilty so they re-write history to make out that the wife is actually the reason that they shagged around, and either left to be with OW, or were forced out, totally unreasonably, by the W divorcing them for adultery.
So - man feels guilty about cheating in the first place, so starts the not-so-subtle routine of picking fault with the wife. Wife doesn't understand and responds to picking fault in various ways, including appeasement. However, cheating H will have a way round ALL of these, because to accept he's doing wrong will --> guilt and his own discomfort, which he can't be doing with.
If wife appeases, he feels she's "pathetic"; if she resists, it gives him good reason to think she's unreasonable.
When he finally leaves/ is kicked out, it's definitely in his own best interest to believe that it's all HER fault, and not his. He's a poor misunderstood bloke who was doing his best, not feeling the love enough, and just had to find it elsewhere.
Of course this works the other way around too! It's just more common for the man to do it.
IME (own and friends) the first 2 weeks after the split is the best time to get anything out of the now-ex. I mean in terms of discussion, truth, and finance. After that, their guilt will be turned to self-congratulation on getting out of a bad relationship - so make the most of those 2 weeks of guilt and get everything possible in writing.
Once the history re-write is complete, the guilt is gone and the ex will now just see the abandoned spouse/partner as an inconvenience, and the more the abandoned one interferes with their new life, the more the re-writer will come to hate them. PLus it keeps reminding them of the thing they did, which, even though it is now completely justified in their own heads, still doesn't look good, so they hate the person rather than their own acts.
It's very boring, but most cheaters who leave/ are forced out, follow this pattern. Not all, but most.