Why is dating a younger man/boy a taboo out there?

I have a strong sense of traditional values and morals. I'm concerned about the trend of older women dating or marrying much younger men, say 50+ women dating guys in their 20's and even marrying. I understand that everyone has the right to make their own choices, but I can't help but feel concerned when I see significant age gaps in relationships. I value mutual respect, equality, and compatibility. I worry that these factors might be overlooked in relationships with large age differences. I certainly don't believe it's proper for an old lady to be wanting to break in a young man in his twenties, let alone engage in that type of activity. Then we wonder why this country is failing and will be judged. This is disgusting to think that this type behavior is acceptable in this day and age, or that an old woman would sink that low. There's no self-esteem, self-worth, or respect for herself, in that.