I agree with you, this change would be very beneficial to the US. I've always felt a points-based system (like Canada or Australia) would make more sense. Nobody is happy with the current system - seriously, not a single person thinks the current US immigration system makes sense. The problem is there are so many competing visions for how it should be that reform is nearly impossible.

Keep in mind, if I wrote a post arguing for a cap of 1.2 million a year, some people would upmod me because it's high, others would downmod be because it's too low, others would down mod me because it's too high, others would upmod me because it sets a firm limit. The number of strong opinions on this topic is bewildering (but not at all surprising).