I understand all of this very well. Those men are not wrong to feel the way they feel.
But if a man IS DAMAGED AND BITTER AGAINST WOMEN, having valid reasons to be that way doesn't NEGATE his damage and his bitterness in any way that would make him a good prospect for marriage to a young woman who does not deserve to be met by such jadedness.
Perhaps the statement that an older man "is probably too damaged or bitter" isn't fair -- but for the ones who ARE, whatever percentage they be of the whole, this quality makes those particular men unsuitable.
If I had a young virgin daughter, I would caution her against ever so much as giving the time of day to any man who thinks she should have to compensate or atone in any way for the actions of the Jezebels he allowed to damage him in his prior pursuit of material gratification. No matter how otherwise qualified he may seem, and no matter his relative age.
Even the older men who do NOT do this, will very probably have some issues that a young, fresh, naïve, innocent woman would have a much harder time tolerating than a woman like me - "sadder but wiser."
Personally, I have an extreme aversion to the notion of women being with younger men. Even if it's by one single day. They can get away with being born on the same actual day, because that's kind of cute, but if he's even one day younger, I'm like "NOOOOOPE, he's a BABY, DON'T DO IT!!!"
Buuuuuut... ultimately I really wish people would stop making such a big deal about the relative ages of fully mature adults. On either side. In any direction.
If you're worried that the man will be damaged, bitter, jaded, etc. because he is older... what you're worried about is men who are damaged, bitter, and jaded.
Young men can be that way too. And not all older men are like that.
(And if I'm so worried that a man will be immature, childish, etc. because he is younger... what I am really worried about is men who are immature, childish, etc. -- not his age. OLDER men can be like that, too!)
Kind of like how not every woman who ends up without a husband in her late twenties/early thirties got there by riding the carousel or divorce-raping someone.
Among sexually mature adults who are seeking mates, relative age should be less about "trips around the sun" and more about actual physical condition, qualifications for the job of husband or wife, etc.
That's kind of my bottom line on using age as a hard filter: it's better to filter for the things you're worried might come along with age OR lack thereof -- because people can "age" in unsavory ways (physical, emotional, spiritual, etc.) a whole lot faster than they accumulate years, and they can also stay retarded for a lot longer than you'd expect in ways that aren't obvious, AND some people have aged gracefully and pleasantly and compassionately instead of becoming jaded and awful (with these unfortunately being the rarest of cases, lol - but they DO exist).
Editing to add: I think modern culture artificially enforces age-peer pairings at an almost MANDATED rate, where a more organic economy would always result in more of a typical bell-curve, with most young adults pairing off fairly close in age, but age-disparity also being entirely expected and accepted as part of the normal course of things for all sorts of reasons, both practical and fanciful.