Imo this has a lot to do with both evolution and culture. Yes, it's mostly (though not exclusively) males who do it, for a variety of complex reasons. It is, unfortunately, part of the mating dance of apes and other species where males by and large compete for females.
We really should teach kids (mostly boys) not to do it. It should be taught in classes at schools, imo. To a lesser extent, we should also teach kids (mostly girls) how best to avoid it. Imo.
Pretty much. Not to open the usual can of worms, but persistence in men is built into how we work. For every woman who is holding their face and shaking their head at persistent guys, there are 5 who end up marrying and having kids with them.
Even as a relatively self-aware man the drive to interact with women is really strong. It takes serious transcendence of your own inborn tendencies to not be annoying. Expecting that from men at large? Good luck.
Anecdote 1: I remember seeing an address by a female, feminist sociologist once. She prefaced it by saying that after she told a colleague beforehand what she was going to say, the colleague suggested she might want to consider wearing a bullet-proof vest during the address (at a woman's conference as I recall), and I feel a bit the same now, lol. What she said was that women are often to some extent complicit in the 'games' being played, that they sometimes say and play 'no' when they don't mean it, and I don't mean just about the sex act (though the speaker did). And that this can cause confusion for many men.
Now, part of the reason for that is to do with 'traditional' gender roles (in the 'game') of which I am not a fan and about which I would agree that
a lot of the roles/rules are by and large disadvantageous to women, historically and to some extent still today. For example, the risk of being thought of as 'slutty' by readily agreeing to sex is one likely factor, and one would have to deplore that. Another factor, possibly much more important and foundational in our evolutionary biology, is that women, for various reasons, have to be much more choosy and discriminating than men when it comes to choosing partners, which may mean that by and large it is easier for a woman to have and want a platonic relationship with a man than the other way around.
There may even be survival advantages in a woman having male 'allies' and some of the 'recruiting' may have to involve what we might loosely call 'flirting'. I don't mean all the time and I do agree that a typical male may tend to see flirting when it's not actually going on.
Anecdote 2: Just yesterday, a female doctor I was seeing (as a patient) was very friendly to me and at one point touched my knee in a very friendly way. I interpreted it as flirting. Maybe I was right, maybe I was wrong (most likely I was mostly wrong). I was able to realise that I was probably mostly wrong by reflection afterwards but that didn't stop the almost automatic thought occurring in the first instance. I probably did, vainly, hold on to the ego-enhancing possibility that I wasn't wrong.
All that said, I think it's really important to stress that biology is not destiny and that biological facts are not excuses. But I think it's very important to at least understand them and to appreciate the nuances. The devil, imo, is usually in the detail, for most human issues.
As to men at large making enough adjustments, I agree that this might be difficult, but I would definitely feel that we should continue to try to make it happen, even if it'll never be perfect, and I'm fairly sure you'd agree.