I'll grant that it could happen to a person that was extraordinarily naive. But to an intelligent and thoughtful person like RL? The probability is so small as to be unmeasurable.
There are many ways to describe Rush, but intelligent and thoughtful don't work. He's uneducated and glories in it. He thoughtlessly pigeon holes strangers with a we/them mentality. I listen to him everday because he's polite, hard working, entertaining, humorous, and optimistic. If he were intelligent and thoughtful too that would be great but I'll be happy with him the way he is.
I remember a very long time ago, way before Rush met Marta, he said on the air he did not make a good husband because he was too selfish. This may still be the case. It may be that he excels in his career but in marriage he is just star crossed. Who knows or cares? It is his private grief and one he will have to work out alone. I agree with those who do not see this as a moral issue. If it is, it is between he and God.
Perhaps Marta grew tired of Rush's obsession with bacon. His two previous spouses both cited bacon fights in their divorce decrees.