Does it matter? Sounds like it's just about labels, who cares if your job is a blue or white collar one, as long as you enjoy it and you are good at it? That's even more true given that "coding" means nothing out of context.
Coding can range from "2 shitty lines of PHP for an outdated Drupal plugin" to "code that'll end up in a NASA shuttle" and yet, both are the result of someone who did some "coding", so it's kinda irrelevant to label coding as a blue (or otherwise) collar job, it just makes no sense.
Also, blue collar jobs traditionally implies physical labor... which coding hardly is. And a white collar job usually implies more intellectual labor... which coding requires, at least in some cases.
And while your comparison to plumbers is interesting, it's not always true either because it's two really different jobs and mindsets, despite some of the similarities you can find. And you know, NYC and Chicago... that's cool, but the world is bigger than that. Culture is a very important factor too in that matter. Where I live, plumbers would make real shitty devs... just like I'd make a real shitty plumber.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.