I think you really don't understand the way some people are. It is pretty simple but you speak like it can never happen that way. People can change. How can you deny that. People can also hide feelings and issues from their partner. You do realize this. Some people have serious issues that the partner does not know that were hidden by the spouse....sometimes resulting in divorce etc.
I don't think you understand sexual chemistry. By you saying that it just doesn't go away or change and it is just a body issue, that is the whole point. You do realize that some people cannot get into the mental aspect of sex with a fat woman right? This happens quite often and some just can't get over it.
Bottom line is that you really can't blame the man for not knowing that their wife would change and not be the same person as the one they married. It happens. Some mental issues, past trauma, or just a lack of caring can surface later in life. Some of the people that get divorced are much happier with their new situation. Happens quite often and I am happy for their renewed happiness.
So you are telling me that people change, but the "bottom line" is that I should not fault your friends for not realizing their wives would change?
People can and do change, but your personality and other mental traits change very little by the time you reach adulthood. Major personality shifts do not happen later in life because some past issue magically manifests itself.
I'll concede there are exceptions to rule (major trauma), but you never brought up the fact that your friends' wives survived a botched sky diving experience/joined the Marines/suddenly remembered they were sexually abused by their fathers and completely shut down emotionally...so I assumed this was just a case of wives putting on weight and husbands not happy about it, so they started having affairs.
The kind of massive 180 you are talking about is possible...its just very uncommon and is usually due to some major life changing incident. Even then you should be talking about therapy, not hookers and divorce lawyers. More likely is the fact that they were selfish and uncaring the entire time or something happened between husband and wife to cause the other to become cold and distant.
I totally get that a lot of men are not attracted to overweight women...nothing wrong with that. What I am saying is that there are solutions to that problem that do not involve divorce or cheating and that those solutions should have been addressed long before it got to the point one was disgusted of the other.
(even pregnant women do not gain sixty pounds in a week)
The real problem may be that we live in such a disposable society. No one wants to work at fixing something when you can just toss it away and get a new one.