Sure, it goes both ways, but I can only change myself. And I have my own set of experiences that feel like the original post is true, at least for me.
And my experiences as a not really beautiful girl tell me, the flirting skills or the personality of the person I'm talking to only make a small difference, at least under normal circumstances.
Since I don't look good (compared to the common beauty standard), it doesn't even matter that I'm a huge nerd, play computer all day long if given the chance, have a hunter's licence, handle my gun really well and sometimes, I'm even funny. I don't even get the chance to show all this.
But then I guess being ugly AND introverted just isn't a good combination nowadays :D