It takes just one cheater that stopped cheating to disprove that statement.
That's true, but I suspect it's also irrelevant. I think the question 2334 is really asking is "What are the odds that this will happen again?" For instance, it's not true that nobody ever wins the Powerball lottery, but if I invest $10,000 in lottery tickets, what are the odds that
I'll win? Low enough that I'd prefer to find a better investment, like say, pork belly futures. I suspect 2334 is not asking, "Is there a remote chance, like on the order of winning a lottery, that my cheating spouse will reform?" but more like "What are the chances that my cheating spouse will reform, and are they high enough that I'd be willing to take the risk?" And I think that's a good question.