Maybe you are seeking a mother figure in addition to a wife.
Ignoring all the Psychological reasons, how about ....YOU just like them?
What do you mean "end up?" You mean you have no say in the matter? You choose to be with them right? I think it's better for younger men to be guided by a few older women before they settle down so they will know what the hell they are doing.
You should know the answer to that better than any of us.
Because girls in there 20s are in college with a lot of homework, so you would have to teach one how to make time for you. Try community college and try for one that has a part-time job, that way you have more places to see her. :)