That's a strawman. Eliminating immigration is not the only way to restrict supply of software developers.
"and not re-legislating immigration policy at the behest of..."
The fact that you felt the need to add a couple of other "baddies" after "at the behest of" should be an indicator that the original argument is weak. This entire thread thread is filled with software engineers making the argument that increased supply of software engineers is going to decrease wages. That's exactly what happens in a free market of labor.
As a thought experiment, imagine a world who got a job offer from a US company was free to move to the US and start working. Any situation short of that is a legally mandated labor supply shortage.
Well duh. But again, that's not the point of TFA.
You're clearly eager to advocate that laborers should be free to move about the world and work wherever they want. That's cool, knock yourself out. But it's another thread than this one.
Even more specifically if there really programmers out there who are best of the best. Making a lot of money would be least of their problems.
Would you also support similar arguments for say, oh I don't know, taxi or hotel prices in the area where you live so the existing pool of taxi drivers or hotel owners can protect the income they are making?