The thing, it's not actually totally inaccurate. The Elementary Education Act of 1870 was perhaps the single most powerful legal instrument that definitively put child labour in Britain into the dustbin of British history, or at least got the ball rolling if I may mix metaphors -- but, it was championed in large part by industry's need to educate a workforce for ... capitalism.
Indeed, even Marx recognized that.
Still, it's really complicated. My dad had to work at age 12 in England to keep the family from starving during the Depression. Was that child labour? Erm, yes. I would venture to guess that there are parts of London where child labour persists underground
. I know there are in the States, for instance.
But I don't think that's what NorwegianVillan was referring to. The implication of his post is that capitalism has often served traditional "liberal" goals, and that's true.