What flirting styles tend to attract the wrong types of men?

For a little bit of context: two of my male friends commented that our female friend of ours flirting method is “inept”, and that it's why she keeps attracting the wrong kinds of men. She was at a different table flirting with two guys when they told me this. I'm confused by what they meant, because it sounded like friendly and playful flirting to me, but I did also arrive late so I didn't get to hear her whole conversation with those dudes. Later that night after those two guys left, one of them dm’d her asking if she could close his bar tab for him so he wouldn’t have to walk back over. She didn’t respond, and when she told us about it, one of my male friends immediately looked to me and said “see??”. I didn't get a chance to ask my friends to explain more as she was around the rest of the night. So here I am asking you all.

I want to genuinely understand how men read these situations, because from my perspective her method didn’t seem problematic? From the snippet I saw or in general really. I'd figure it was just that dude being problematic alone. To be honest she does attract the wrong kind, I do agree with that.

So I would like to know what NOT to do so I don't do the same. I haven't had the best luck with finding a good partner either.

So my questions are... A more detailed explanation of what my male friends meant, I'm still not fully understanding what they mean.. Is this more about what’s said, or tone/body language/energy? What flirting styles would attract respectful men? What shouldn't be done to avoid opportunistic ones?

If any of that made sense