I’m sure the developers make the lower half of six figures, but they still have to sell their labor to survive, so they’re still working class.
I’ve been an SF Bay Area software developer for almost thirty years, so I know them well. I consider us members of the professional–managerial class (PMC). We generally think we’re “above” the working class (we’re not), and so we seldom have any sense of solidarity with the rest of the working class (or even each other), and we think unionization is for those other people and not us.
When Hillary Clinton talked about the “basket of deplorables,” she was talking to her PMC donors & voters about the rest of the working class, and we eat that shit up. Most of my peers have still learned no lessons from her election defeat, preferring to blame debunked RussiaGate conspiracy theories.