What happens in reality most often is that when two people who do not know each other well decide to marry, they might, at a later stage, discover some personal incompatibilities, such as hygienic or sexual incompatibilities, which can be the most repulsive, or less stressful but nevertheless important in a marriage differences in educational or cultural level, pace of life, circle of social interaction, etc.
For example, for a woman who lived all her life in a large city and was attending theatrical or musical performances on a weekly to monthly basis, the fact that her husband lives in a small town and never attends live performances can be significant enough to feel inadequate in a marriage, if these cultural activities were important for her.
Apparently, if immigration scams in marriages with foreign women were indeed such a problem, you would have heard horror stories much more often, and, eventually, your government would do something about it.
so many Russian women that seek somebody abroad with the only purpose to use marriage as the means to immigrate to the USA or any other country.
In the long distance dating, couples prefer to concentrate on their common points and overlook their differences, or possible differences, and a couple can be forced into a marriage decision before they are actually ready to approach such a decision.
It is only women who are absolutely desperate that would contemplate such a marriage, and those women are seldom objects of desire for any man.
A woman that is desired by a foreign man is usually a woman who can exercise some choice among her suitors, and she would rather select a mate who is suitable for her than just marry anybody: once she is in a foreign country, and divorced from her husband, what will she do?
Scandals, murders, and scams make the news; happy marriages don't.
In the USA alone it's about four to six thousand men that marry foreign women every year; how many scandal stories you hear for the same period of time?