I have similar views to many of these guys - alt right, anti-feminist.
Maybe I can help to describe how some of these men feel (but I don't think it applies to all of them, some of them don't deserve to be on the list).

If you really think that your own race of women have been corrupted, it is natural to look elsewhere. Traditional morality held that a woman should be chaste before marriage, that the marriage vows were sacred, and divorce was either illegal or scandalous. And also, women would stick to more feminine/maternal activities.

I do deeply resent the fact that these things have changed. If you are a white man looking for a wife in the modern environment, you encounter women who care more about their careers than getting married, who might not have a strong desire for kids (they've been told it's not important), who might have had a lot of sexual partners, and who have a divorce court system in their favor. I don't know for sure if this is true or not, but let's assume it's also true that obesity, drug use, alcohol abuse, and tattoos/piercings are more common now than they were for most previous generations.

So if you're in this environment and you don't like it, you might feel that it is too hard to find someone you're happy with. It is tempting to say "screw this" and go somewhere the odds are in your favor.

It's sort of like the conservative white guy is a foreigner in his own country now. The culture he's swimming in just doesn't feel right. Maybe it's like being a freshwater fish thrown into the ocean.

But as I wrote on a post here the other day, I do now think that it is a mistake to date outside your race as an escape from what you see as the current defects with your own culture. And it's particularly unfortunate if you find someone who will marry you not for you as an individual but because she values your race.

Ultra-conservative white men who are tempted to go Asian should remember:

"It is not the strongest of the species that survives, nor the most intelligent. It is the one that is most adaptable to change."