"But surely (undeniably) each year the United States already enjoys large numbers of immigrants"

Agreed. I do not think that is the point of argument here. US overall has huge number of immigrants every year. The problem however is how they determine the eligibility. Family based permanent residency is much easier to get if your spouse is a US citizen no matter what your qualifications are. That is understood considering families need to be united. But why are the programs such as EB-5 investor visa so poorly designed ? If majority of those visas are going unused every year, why dont we instead try and correct it so that it makes it a little easier for aspiring foreign entrepreneurs to apply. Do we really need $1M to start a business these days ?