Let's start by wondering if he really likes her. The fact is that not every male can understand this. It depends very much on the character of the man.
Now many authors of works, psychologists, and just ordinary men believe that in our century is gradually coming to an end the existence of feelings like love, described still Pushkin. That the increased speed of our lives, the desire for success, power and money make us armor-piercing, and feelings, including love for a woman, bounce off us like stones from iron. Of course, it is not. However, some men, especially young men, believe that a certain rudeness towards women (of course, within reason, otherwise it already turns into insults) gives them a certain masculinity and "coolness. And the consequence is often that a woman, especially a young and inexperienced woman, believes that this man ignores her.
In fact, it's not like that at all. There can be at least two options here. Very often such behavior of a man (especially a young man, although in our time the concept of "youth" often applies to the age of up to 30, if not 35 years) is just a mask, which hides either inexperience in relationships, or the fear of not justifying the trust of this woman or be untenable in any type of relationship. Well, the second option is that maybe he doesn't like it very much, and he doesn't try to hide it. The first reason is the second one. It consists of the fact that one of the most common current male qualities is infantilize. After all, 80 years ago and a 20-year-old boy was considered an adult, and now his mother can say a phrase about a 30-year-old man like "he is still young to get married, he is only 30 years old". And this can be said, even if it has been a few years since his beloved son is thirty years old...
And as a result, such a young man is simply afraid of binding himself to some kind of commitment, because a woman needs to be cared for, and then the children may appear. What kind of children can we talk about if he is a child himself? Such a person needs a special woman who would take the initiative and bring this "adult child" into the state of a man, having defeated his mother at the same time (which is often a more difficult task).
And the negative experience acquired by a man as a result of relations with women does not contribute to positivism in his relations with them. After all, the offense inflicted by a woman becomes a strong blow to male ego, and it takes a lot of effort and time to throw off the received negative. And the time required for this also depends on the strength of the character of a particular man. Being under the influence of negative experience, it is difficult to determine your attitude towards a woman.
It can be such a situation that the woman you like will not meet the expectations of the man. Here I do not take into account her financial insolvency, which does not satisfy a man. The relations of calculation are not the subject of the article. I want to say about the behavior of a woman, the level of her intellect. After all, even a very pretty girl can scare away another man only by "opening her mouth". If a man is intellectually developed, he will not be able to build a relationship with a woman who does not match his level. Well, she may simply not understand why this, seemingly pleasant, man left her.
Many men may not like some of the habits of women. For example, smoking. Now everything goes to the fact that smoking people are more among women than men, and those who do not want to have a smoking girlfriend next to them, there is nothing else but to make her break with the habit. Or he will have to part with her. Although here are possible options.
Or the man does not like the fact that the woman does not prevent other men from flirting with her. Some people will only get excited and flattered by the fact that their woman is noticed, others will not like this behavior. Depends on the nature of the particular man.
In general, the last three reasons, in my opinion, are "treatable". It is common for people to change, and a woman may like a man, change her behavior, or give up her bad habits.
Now the situation in the world has changed very much, even in comparison with the approach to life that existed thirty years ago. There are such concepts as political correctness, globalism... And feminism. Of course, it existed before, but only in the XXI century did it take, as it were said, legislative forms.
That is, if the punishment for rape has always existed (at least in the twentieth century), such an offense as "sexual harassment" is unlikely to be more than 20-30 years old. But this is an article of the Criminal Code of many countries! And in many countries, the victims of this article were many politicians, managers and high-ranking military officials.
And men observe these processes, and many people get the feeling that if not all of them, then many women belong to such feminists, and you can expect anything from them, including ruined life and career.
Russia has not yet reached such a chaos, and in the U.S. and Europe, many men are simply afraid to approach women, even those who like them, in order to avoid problems. But the most important reason for a man, in my opinion, to "ignore" a beautiful woman is that he is not free. After all, polygamy is not a common quality of all men, and the feelings of a woman that some man likes her can be subjective or simply deceptive.