Horses for courses and just accept we are not all the same, and also because people have different social etiquette doesn’t make them rapists or perverts.
True, it doesn't make them that. They can come across that way however.
However someone who has come across those who do not take no for an answer, who invade personal space, who lay hands where they shouldn't, who has a lack of respect from particular individuals - that person may well react badly to someone pushing boundaries they should not be testing.
Think of it from your own perspective.
Don't answer, I don't want to know and I'm sure some other people may be uncomfortable knowing but just in your own mind imagine this.
You work in a company, you are yourself - a male colleague comes up behind you and slaps you on the bottom and walks off.
Later that male colleague slips his arm around your waist and hugs then walks off.
Feeling uncomfortable? Feeling annoyed?
Now fast forward a few years, working for another company, you are in a buyer meeting and at the end of it a male buyer leans over and tries to kiss you.
Feeling uncomfortable again?
Humans can feel uncomfortable in many situations that for another human may be all right.
What you and I accept or find uncomfortable may be different than what another person finds acceptable behaviour.
Humans in a particular society tend to deal with different comfort levels and societal habits by using a semi standard set of protocols useable in polite company.
Handshakes. Politeness. Showing respect for the other person. Working to not make them uncomfortable. Artificial behaviour that in a more social setting may be overridden by your social protocols.
At work you can behave one way while on a works night out you may ask that young lady in accounting for a dance. Behaving differently as different expected behaviour.
Oh, and if you don't like the kissing thing, an air kiss is acceptable in some cultures. I'll kiss my mum on the cheek, not my sisters.