Yes, you can come up with all the explanation whatsoever you want to how this is a ~local maxima~ of happiness, but the fact is that we live on a much higher one with tons of disposable income and benefit from their work... so it s not a ~global maxima~ (not even close) so we should do better.
What can I say? I'm definitely more to the left than most people in this website but any quietly upvoted defense of child labor sounds like "the slaves had it better than in _x_" or "women were spared _y_" jobs to me when it comes to defending poor social policy. Grown-ass white men getting paid to develop digital toys justifying to themselves why the situation for 9 year old sweatshop workers is good enough. JFC.
edit: in fact, every single reply amongst the first 20 in some ways works to justify the completely bubbled-in mentality of the startup crowd. just running down the topic I see (caricaturized for effect) "social justice types don't understand how rough it is out there, this is good for her!", "ugh, this journalist is endangering the girl!", and "this really puts in perspective all those pesky cultural issues that women, gay people, and minorities keep complaining about".
what the hell is wrong with you all, seriously.