I didn't suggest anything of the sort. I said that maybe companies are paying their employees much less than they could, and that maybe employees aren't getting a good deal despite wages being high relative to other industries. I didn't say that all of the value an employee generates should go to that employee - just maybe it could be more than does right now.

If not, then why should employees expect to make more than the market rate for the labor they provide?

"Market rate" is basically the median negotiated salary for similar roles. There's an assumption that a salary is like a price, and supply and demand will drive that price up for in-demand skills. This is the part I'm challenging. I don't know if price theory works for salaries where one side of the market (employers) has far more information and leverage than the other side (developers). If most developers are bad negotiators then getting a "market rate" salary means you, as an individual, are being paid the same as the other bad negotiators, and you actually lost out on getting a higher salary.

It could be that using the market rate to derive the appropriate salary for a job actually keeps developer wages lower than they could otherwise be.

At this point this is all just futile speculation though, and no one is going to change anything so we might as well just accept it.