Everyone is different. Some women marry for love/soulmate, most women marry for a family, some marry for green card. Some even marry just to leave their parents.
In every Asian country, local men criticize women in their country marrying out, as they see women as a kind of resource.
In the old days where U.S. and western countries were much richer (compare with Asia), Asian women did marry American men for a better life. Now things have been changed. Educated and wealthier Asian women are seeking men of good qualities for their life-long partner, not a bread earner.
If I were you, I would worry about the cultural differences. Firstly, Asian women do NOT accept casual dating - that is an insult. Sex is for husband only, not with other men! Those who jump onto your bed, be aware.
Once you are involved in a sexual relationship, you're supposed to "take the responsibilities" as a husband. If you don't, you're a bastard. You may be able to run away, you may not, and beware of karma (or curse).
Once married, the marriage is supposed to last forever. If you don't do your best to make it work, you're not a good husband. If you have affairs, you're worse than an animal.
In U.S., marriage is only a "partnership". It lasts as long as it works. To Asians, marriage is holy and it should last a lifetime. A husband is supposed to care about his wife, financially and emotionally. He is supposed to at least send some money to his parents-in-law.
Never ever think that you should split the expenses at any time. Man are supposed to look after his lady. If he cannot do it, he's not ready for a marriage.
The reason for such culture is because in Asia, women are so disadvantage in society. They can hardly find a good job. Income is much lower and work-place sexual assult can be big problem. Asian women have to find a husband that can support the family and feed their babies. Asian women, in general, are much less physically strong. They need good care and comfort from their lovers.
I hope this help you understand more about Asian girls. If you're seriously looking for a wife, God bless you. If you're looking for some great sexual experience, I would suggest you tell them at the beginning. If they don't mind, you're fine.
Asian women who get involved with Western men are not looked down back home because they want to marry a Western man, they get looked down because they sleep with different men. People think they are dirty and shameless. So, please, act like a descent American man.