I see what you mean with certain jobs being perceived negatively. Maybe the messaging should be about the value of "unskilled" labour/labourers rather than saying that there's no such thing as "unskilled" labour? To me, the latter implies that there's nothing distinguishing "skilled" and "unskilled" labour. The only people who would understand what you're really trying to say are those who are part of your circle spreading the "message", and thus it only serves the purpose of saying "I'm on team X! Anyone else?"