It works for many, though. My sister was 19 and her husband 33 when they started dating. They've been married over 11 years now with four children, and both seem happy.
In the not too distant past, men regularly married women significantly younger than themselves. Celine Dion's late husband was much older than herself, and in a recent interview, she said she would never remarry because he was her soul mate. It is not outside the realms of reality for May to December relationships to work.
I tend to be a problem solver. When I read about a problem, I want to offer solutions. This seemed like a solution to his problem.