The presumption is more of a practical and amusing one. Many of the villages are funded in part by remittance from US and this country was saved by US from literal mass rape by Japanese in WWII and unlike other countries we never seriously fucked them afterwards so the people overall are very cheery in dealing with Americans in my experience.
1. The term predates the world-wide web to a time when women in developing counties would be in a literal catalog, and correspondence was done via mail.
You can educate them on all these things (many of these brides surely already know this) and yet many would still choose on their free volition to proceed ahead.
But they are the ones who created the gender imbalance. It's completely self-imposed.