To an extent.
Everybody acts according to their experiences. It would be stupid not to. As someone once said, experience is what you get when you didn't get what you wanted. You didn't get a promotion, or managed to escalate the relationship. But you have the experience, some more knowledge of people and what went wrong. You store this in the back of your head and when faced with similar scenarios, you look back at your experience. If people don't look to their experience, girls will date the same *******s over and over again, some people will never get that promotion, some people will never lose weight as they try the same approach. The definition of idiocy is to make the same attempt over and over again, expecting a different result. What I am saying here is, that if you have a certain experience with one type of people, you will use that experience and it is natural to do so. Everybody does. If a particular negative experience is related to people of a certain nationality, they will not speak up about about it, at the fear of being accused of racism. But they take their experience into consideration nonetheless.
Experiences will always beat research for most people, but research comes in at a close second. If both experience and research gives a certain idea of a type of people, I don't blame someone for making generalizations based on that.
In the end, we cannot know everybody first hand. We have to base our assumptions on a combination of experiences and research. For some reason, some people do not consider it wrong to make generalizations in positive terms ("Italian people have such a great sense of style") but it is considered wrong to make any negative one. They are both rooted in either experiences, stories or stereotypes, and one is not more wrong than another. The difference is one of them disagrees with politival correctness.
Another factor to consider is why someone is making a generalization. It may not be an actual idea of "all people are this way" as much as the possibility that "most of them are". I would guess that hardly anyone actually makes strong generalizations. The common belief is that "they're not all like that, but many enough for it to be something to look out for". I have never encountered a single person claiming that ALL Muslims are terrorists or that ALL poor people are lazy. They may come across that way in their argumentation, but it is hardly ever their point of view, and most people know that, deep down.
People will calculate risk against likeliness against loss. A woman may be waling down the street, alone, at 2 am on her way home. She sees a man coming in her direction, and she will take the phone out of her pocket and call someone or walk to the other side of the street. There is a chance the man may notice this. He may be upset that he is considered a threat, or if he's paranoid, upset that it is related to his appearance or ethnic background. I would not call this a "generalization". It doesn't mean that she is thinking "all men are potential predators" or that all men of his type are. But the possible horrible outcome is so terrible that his potential hurt feelings is a cost she'll calculate in as worth it. And it makes sense.
If a woman is raped, she may make sure she will never walk alone after midnight again. There is a good chance nothing would happen to her if she did, but is she crazy for doing so? As another example, let's say a guy from a working class background starts school in an area with a lot of 'posh kids'. The upper middle class guys makes remarks on his clothing, they ridicule his accent every time he raises his hand in class, they humiliate him in front of girls. In short, they make his life hell. When he is applying to uni, he makes sure the unis he's going to have students of all backgrounds and a mixed demographic group as he does not want to go through the same thing again. Is he generalizing upper middle class people and therefore an idiot? Or is he merely making choices based on experiences for his own good? Is it possible that his choice is made knowing that not ALL upper middle class people are like that, but many are, and many enough to avoid schools whose student demographic is very different from his own? When people having dating preferences, it is rarely questioned. But these preferences are, whether people admit to it or not, rooted in experiences and perceptions as much as attractions. When knowing about traditions within Muslim cultures, a Western girl who's used to absolute equality would avoid Muslim men. She may say it's rooted in attraction, and it may very well be, but the perceived cultural differences are a great part of it. If we would go out of our to disprove every perception we have, how much time and effort would it take? Would it be worth it? Am I suppose to date men of three different religions or national background to be sure I am not making a generalization when saying I prefer French men? It would be meaningless, while I would be spending my youth and fertile age on men I knew with high probability would not be right for me.
Anyone who say they do not possess any kind of generalization is lying. And they are necessary, to an extent.
There are subtle examples of dealing with experience, such as someone being screwed over by a car salesman and making sure they are asking extra questions next time they buy a car. There are extreme examples of it, such as a man being rejected by two women in one night and concluding that "all women are shallow sluts".
To me, it depends on the extent of the generalization. Dismissing an entire gender would be ridiculous, there are just as many men as women on the planet, so statements like "all men are *******s" or "all women are sluts" fall on their own irrationality.
A big part of intelligence is, in my opinion, being able to separate "in spite of" and "because of". A lot of people are incapable of this. Every time you bring an example such as "men don't like short hair", you'll get hit in the face with a snowflake comment along the lines of "my friend has short hair and boys love her" (by snowflake comment I mean "I am that special snowflake whose experience disproves all research ever made). Nevertheless, long hair signalizes femininity and fertility and men prefer it. Most likely, those men like her friend in spite of her hair, not because of it.
I am not entirely agreeing with your last statement. Logic and emotions are two different things, but there is a reason we are equipped with them both. There are matters which you must think of logically, and some you must think of emotionally. When you are dealing with other people and relating to them, you are using your intuition and combining your logical sense and your emotions. If nobody ever got in touch with the empathic side of themselves, the world would be a slaughterhouse.