More experienced people can probably come on other visas, like O-1s and EB-1s or 2s, but restricting the H-1B also severely restricts the international talent that is already here and graduating from U.S. universities that then wants to stay on after their OPT.
Many countries have started to make it difficult for foreign students to stay on after graduating from their schools. I think doing the same here will be a big mistake.