the problem is, most guys just go about it the wrong way. It’s good to compliment someone. It’s bad to compliment someone like your compliment is payment for service. “I just told you youre hot, now let me fuck you!” Compliments are meant to be given for the sake of giving. Not as a means of transaction.
They also do it at inappropriate times, like hitting on women who are working and unable to escape it or be forthright about their discomfort because of the requirement to be polite and friendly. Or they’re working out and wanting to be left alone. Or just walking down the street minding her own business.
In order to effectively flirt, you need to have a keen understanding of body language and a lot of men who are creepy and too aggressive simply don’t