This is a meme coined after a critic’s observations of women who inspire men through their superficial flaws. They have quirky behaviours that are construed to be weirdly endearing.
But when taken out in the wild it inspires a different, albeit mixed response. One that combines humour, revulsion, pity, schadenfreude, horror, ridicule and cynicism.
There was an article on Nerve on a woman who tried to act adorkable to impress her boyfriend only to inspire the opposite. Also if you hang out at websites that ridicule lolcows (people whose eccentricities are amusing in a sadistic way) a lot of MPDG could be those.
While it’s wrong to ridicule those that stand out, it’s also wrong to put it on a pedestal or tolerate such because there comes a time when your tolerance and patience gets tested until it cracks.
I suspect superficially offbeat female characters are appealing to insecure people though not all insecure people like those. Or that if they’re actually flawed and awkward, they’d be too human to be considered quirky.
They’re ultimately boring though it’s probably harder to give them actual struggles, shortcomings and the way people react to them to keep them from being MPDG.