Not impossible, just wholly ineffective for the majority of men out there.
99% of men out there are good guys. They have interesting things about them, and positive character traits. The ones that succeed with women are those that make an immediate impression, get their attention, and offer something DIFFERENT than the 99% of the other guys saying 'Hi, come here often' or 'Hi I noticed you across the bar and thought I'd say hi'. This actually gives them the chance to show their positive traits, whereas most guys lose a woman's interest before they have a chance.
You don't like the lines or strategies in the PUA scene? Me neither. I make up my own shit now that I've internalized the whole notion that a woman should be impressing me, not the other way around. But that, in of itself, is already a different approach than 90% of the guys out there.