I strongly agree that many - if not most - were scams...but it still resulted in many Russian women coming here on fiancée visas, and American men going over there to find wives since they couldn't woo one here...or if women from that area were their particular fetish (as seems to have been the case with Trump).
But it's nothing unusual - women from poor nations have *always* done whatever they felt was necessary to make their way to a more prosperous place - anyone who's served in the military has to have seen this - and at the time, Russia was dirt-poor.
And when the men of a poor country see the women leaving for men in a richer nation, there is often deep resentment. It's a human thing.