Dunno why you are downvoted, most of what you said is spot on. Most of US immigration is diversity-based. Even employment-based GCs have an element of diversity in the form of per-country limits. Only investor GCs, and maybe Einstein visas are probably not diversity based. Lot of ignorant comments in the replies that still miss the point that H1B is a temporary permit. So if people choose to have kids here and buy houses, that’s their choice that they made fully aware of the chance of having to leave the country. Playing the victim card after making your choice with all the info available is just silly.