In my opinion, when a woman agrees to live in a civil marriage, she voluntarily agrees that the man does not take responsibility. Men and women are arranged in such a way that over time, in any relationship, a woman's affection remains, and sometimes even increases, while men, on the contrary, weaken. Thus, in a civil marriage, a man becomes more and more free, and a woman becomes more and more attached to her beloved.

Again, the psyche of men has such a feature - they will never change something if it is already working. So, if there is already a woman nearby who is waiting at home, cooking, cleaning, and so on, why should this be changed?
Add to this the excellent conditions for the retreat of the strongest of the pair. Packed up and left, and no problems with the division of property or alimony. It's like if you were first given, say, a car, you've been driving it for ten years, and then they came and asked you to pay for it, like for a new one. Would you pay???

Some men are so afraid of the notorious formalization of relations that there is a feeling that for them it is like signing their own execution. Why? Men need a sense of freedom, so they feel much better in cohabitation. But this is not the only reason. Psychology explains this fact very simply: infantilism and, as a result, lack of responsibility. To marry - to vouch that he is ready to take a woman completely, along with all her tantrums, whims and shortcomings, and for this you need to be a mature person.