The first reason is that there is a great lack of men In the Ukraine as well as in Russia. To understand what Ukraine men are now and why beautiful Ukraine women do not want to create a family with them we should look back on history.
Before the revolution there were no problems with marriages, but after it a turn of reprisals began when the whole estates of men (officers, aristocrats, doctors, scientists and businessmen) were either killed or forced to immigrate from the country. Many of them were sent to Siberia for the rest of life. People from the lowest layers of society have got the power. Many churches were destroyed and drinking was flourishing in the country. Then after the second World War many men died and there was hardly any family in which no son, father or brother died. There were many boys brought up only by mothers. In those times Ukraine women got stronger physically and morally. And now Ukraine women often recall in their memories this war that took many men.
Another reason - many Russian men drink a lot, they began to do this especially in 1990s, when decent changes took place in the country. So Ukraine women had to think about everything, especially how to get money and how to feed their children. Emancipation of women was growing and the roles in the family were somehow mixed. Ukraine women became the head of the family.
The third reason is that Russian men are mostly weak, dependent and spoilt. They play secondary role in the family relations cause he can't take care of himself to speak nothing of his own family. They are not adjusted to doing something as most parents are over-indulgent. So they expect Ukraine women to do everything instead of them.
Then there are economical problems in the family. I won't go in detail describing all the problems a young family can face. Young families are mostly dependant on their parents that's why there are so many divorces in the Ukraine. After the divorce it's very difficult for Ukraine women to find a husband in their country. But for foreign men it's ok to marry a woman with a child. Moreover they are eager to help their wives not only with the child but also about the house. For Russian men it's absolutely unacceptable as he thinks that he provides his wife with a child - and that's enough.
According to all these reasons Ukraine women are a bit disappointed with Ukraine men and search foreign husbands for themselves and fathers for their children.