It sounds to me like you're pretty much arguing that the work visa a a really cool business model. WHEN IT'S BEING USED CORRECTLY.
My "saga":I have a few years ago worked for a very large American company. And in my country, admittedly, there are about 50 times the number of IT jobs available compared to the amount of unemployed IT people (Bachelor degree equivalent or higher education).
this puts (and still does) a higher price on talent. And i've benefitted from that, certainly. I wont deny that. But I've ALSO been taking paycuts to finance improving working conditions, re-educating obsolete talent and a few other things.
So I was appauled when I found out that MY company, whom I had worked for for over 10 years, had started, not only "importing" foreign labor, but underpaying them, AND lying about it to the government (otherwise they couldn't get a visa, if the salary officially wasn't high enough), AND forcing the hirees to pay a "deposit" of roughly 2 years salary, payable to the company should the hirees, for ANY REASON be dismissed from their work within the first 2 years of their employment. downright blackmail.... They underpaid, they lied and cheated the government and their own employees. I immediately handed in my resignation and found a new job. Sure the new place didn't have the benefits I had fought for over the last 10 years, but at least the new place was honest about it.
And the new place also hired foreign talent, but did it according to the rules, and only because staffing was a pain, and took forever.
Bottom line: There are liars and cheats out there who will do anything for a buck, but there are also businesses who will act morally, legally and ethically correct. The trick is to be able to tell them apart. And I believe that if the OOP is in the a situation where someone else was hired under the rules, at his/her expense, then that's just tough luck. If that person was hired, bending the rules, then it's abuse of power, not discrimination. I see many problems with this type of hiring, but I do not see a discrimination suit being won...