- It would alleviate (though probably not solve) the downward pressure on salaries.
- It would ensure that companies are well motivated to find domestic workers since they would, theoretically, be cheaper.
- It would ensure that H-1B's go to the people who would add the most value to the economy (or else the company would be less competitive due to overpaying).
- It would favor the most talented foreigners rather than putting them in a random lottery with new grads.
- It would allocate the H-1B's to the companies that need them most (since they're offering the most money)
- It would maximize the future tax take of the US government (maximum income => maximum taxes paid)
Ironically, this might have prevented me from getting my own H-1B as I got it fairly early in my career.