The "replacement of an American" is where the narrative breaks down. Traditionally we haven't had large numbers of unemployed developers. One of the consequences of the the Dot Com bubble bursting is we lost an entire generation of native-born engineers. People weren't going in to CS. At the same time there was an explosion of software positions. This is part of what fed the increasing use of H1B talent. This was also one of the sources of the bootcamp phenomenon. Things are bit more dynamic these days. This is just a nativist, anti-immigrant move.