>>516630610 (OP)
Pay close attention to what it doesn't do.
>DOES NOT apply to individuals already in the U.S. on H-1B status, or to student visa holders on OPT seeking to change their status to H-1B.
>It applies only to individuals outside the United States who are being sponsored for H-1B visas and seeking entry. This is specifically aimed at the Indian IT outsourcing companies whose business model is to sponsor large numbers of foreign workers abroad and bring them into the U.S. on H-1B visas. They may shift to sourcing workers who arrived on student visas or to heavily utilizing L-1 visas.
So the student visa to H1B visa pipeline is still active. And H1B's currently in the US are unaffected, although if any of them leave the country and try to re-enter, it will go badly for them.
Companies like Google and Microsoft don't use H1B, they use L1, which is unaffected by this legislation. Those companies source their IT workers exclusively through L1 and student visas. This is why tech workers say they support this legislation.