I have to agree with every response here:
I think the "lack in relationship skills" translates in man language to "not eager and willing to 'honor and obey' me, raise my kids, clean my house, cook my dinner...."
Even in my mom's time (early 1960's), the norm was to find a good husband. If women went to college, it was primarily to husband hunt, not get their education. That was just what was expected of you as a female. Then there was this wonderful era of rebellion and civil rights movements, including Women's Lib. People, men
and women, were appalled at some of these ideas. They broke apart the family and were immoral. (Read Betty Friedan's
the Feminie Mystique- it was terribly criticized for demoralizing family values. But to read it today, it's nothing special.)
Unfortunately, these ideals still exist to some level today. I personally think that some men are oftened threatened by independent, strong women because they don't know what their own role is suppossed to be in the relationship- how can they both be breadwinners? What will happen to the kids? What! you don't want kids? That's your
job as a woman?!
Granted, this is a slowly dying mindset, but I mean slowly. And I support any family's decision to have one parent (mom or dad) be a full-time, stay at home parent. But I don't see this as the only option.
Anyways- I know I got off on a tangent there

So, James, I think in most cases, the values and attributes the men you mentioned are/were seeking in a wife weren't available to them in American form, so they sought elsewhere.
It's also possible that the women they were dating in the States didn't see the men as desirable husband material, or simply didn't want husbands. Forcing them to look elsewhere.
*Edited to add this*
James, I know you said leave the men out of it, but really-- women have been dealing with men's lack of relationship (and general communication) skills for centuries. Women in America finally feel like they can say "No, I'm not dealing with your mind games, childishness, lack of communication skills...." whatever. And not be so chastized for it. So it's also very possible that the men you mentioned are the ones lacking in the relationship skills. And the women they were dating weren't having it. (To go along with my last paragraph above).