While I agree with this, I think part of the stigma is that "blue collar" jobs tend to be the ones that get outsourced, automated, or made irrelevant due to technology and internationalization.
And there's really not much empathy when that happens. I remember some of the elitist attitudes taken toward the out-of-work coal mining communities that were a hot topic during the last election cycle. I'm not trying to make a statement about which side is right/wrong, but it makes sense that people in general prefer to avoid "blue collar" work, with that sort of a national attitude towards it.
With a college degree being the de facto minimum bar to fields with some semblance of lifelong job security, it makes sense that people will attempt to acquire one, no matter the cost.