I think a lot has to do with whether you mix (in any sense) with more women or men. Shop assistants are more likely to be women, so of course you are more likely to be badly treated by women in that context. You are equally likely to be well-treated by them, too.
If the majority of colleagues at your level have been women, then again, you will base your experiences on that, just as you will if the majority have been men.
Speaking for myself, I have been most hurt by people I have felt close to, regardless of sex, but equally, I have had the most joy, love and support from close friends, too. I would imagine most people would say the same - it is difficult to be hurt by someone you don't care about or know well.