I meant "blue collar" as a metaphor for employing a large group of regular folks, not for outside work.
Manufacturing jobs in the middle of the 20th century were a core part of the economy. As robotics and other forms of automation replace more human activities, computer programming might become somewhat similar to the assembly-line job of the past. If not, I can't think of anything else that could plausibly take that role, in which case there would not be a large middle class.
There seems to be little connection between the category of blue-collar work and programming other than it is a form of 'building'.
The crux of blue-collar work is that it predominately involves physical labor and does not require 'skill'. That's not a literal interpretation, that's the core meaning -- programming is not analogous to physical labor or 'unskilled' work.
The former, yes - the latter, no.
A boilermaker or a welder is a blue-collar worker, but doing either requires a great deal of skill.
What it does not require is 'artistry.'
If you drop the physical labor requirement, some computer programming tasks can be performed by folks without much education.
Manufacturing has historically been a low-skilled, not un-skilled job. Programming can be, too, if we change the way we teach.
Also, the nature of programming is the ability to automate away white-collar work. We're probably going to need new categories, once many of those are gone. We might end up with engineers, a service-worker class and a managerial/executive class.