This will probably never change.
Given that the union I was talking about above is specifically one that would be formed by ISVs to protect its member employees from being coerced into bad working conditions by their managers or the clients their demands come on the part of, I assume that "not having to maintain software in perpetuity with increasing labor-load" is probably one such ideological point they'd be likely to stand behind, among others. (Or it might not be; either way, I still think "union that can disbar programmers" is an interesting solution to the problems that programmers do care most about, whatever they may be.)
Remember, the point isn't to punish the disbarred engineer--they likely were coerced into the practice. The point is to signal to the companies who would attempt such coercion, that it will result in their engineers being removed from them, so they shouldn't bother. (Yes, the company's name might also be blackballed in the industry, but that might not matter to the company if they're still able to make money. On the other hand, having no engineers who would ever want to work for you, for fear of what it would do to their careers, would matter.)
"Sure we can update from Win32 to $modern. We estimate it to take between thirteen to seventeen man-months. You know the usual rate for a man-month, let us know when you want to start the project."