I saw some commenting about this issue in a Swedish paper. The men were being sexist in a way that they would only dare to do anonymously online...
They were essentially saying "well Thai women are better than Russian women because the Russian women are so materialistic and want stuff and expect to be treated like a lady. Thai women are more submissive and accepting".
This is because Thai women are not as corrupted as Russian women yet. But I expect this not to last long...

In Kiev last summer I saw a girl of about 18 sit at a cafe and talk to a big American twice her age and size - clearly about dating related stuff.. She could hardly string a comprehensible sentence together in English, and he clearly wasn't paying much attention to what she was trying to say anyway. If that's the beginning of a "serious relationship" it would just fall to pieces once they actually are able to communicate....! If it was something else, taking place in broad daylight at a cafe then it is even more shocking.
I regularly see girls trying to catch the attention of blacks and Arabs near Russian Kremlin in Moscow. They would not even look at me. They also very much love the people from the Caucasus (Dagestan, Azerbaidjan etc).
It is indeed surprizing because one cannot expect those people to have more money than an average Russian.

In Soviet times you could get foreign currency from Westerners or move to their country, but what makes now thousands of Russian women to marry Africans, Turks, Arabs etc - I have no idea. Some even go to Egypt or Turkey to get fucked (similarly to how men go to Thailand, Brasil or Philipines). There is a lot of Russian wives in Syria: there are even communities of Russian wives to Syrians in the Internet. And this is not only Russian phenomenon. I have read that in Israel there is a lot of Jewish women who marry Palestinians (despite Israel has serious shortage of women), while there is no opposite process: there are virtually no Palestinian wives to Jews.

I only can explain it with an assertion that women prefer people with lower IQ which makes a man to appear more primatic.