Really? An H1-B is REQUIRED to go home after 6 years. (Where they often take the skills they learned here to start/work for companies that compete with their former US employer.)
The H1-B policy is flawed in this respect. These foreign workers should have the option of staying here and attempting to become naturalized American citizens if they so choose.
Even so, if I am better off hiring them, I will make more money, which I can then spend or invest, which will ultimately create more jobs and wealth in the American economy.