You don’t know what alienated him from his wife. Neither do I.
Why is it so difficult to believe that he could have rightfully grown alienated from a dreadful spouse?
it is difficult to believe because there is absolutely nothing, in the public domain, to indicate that;on the contrary, there is PLENTY to indicate that he was the reprehensible one. so, you can make counter-intuitive assumptions. But, logically speaking, he is more likely the wrong-doer.