The problem with your solution (and similar solutions - e.g. implementing "salary auction" for H1B - i.e. it's not a lottery, but it's that the most paid get the visa) is:
It requires changing the law.
Which is very difficult, and requires a broad coalition in 2 houses of parliament.
On the other hand, executive orders are very easy.
I wish the better solutions get implemented, but until they are, we have to seek alternatives.