I too find his remarks highly racist. I've been working in Silicon Valley for 20 years and at all of the companies I have worked at there has always been a large percentage of immigrant engineers of all races. Most of the start-ups in the valley were started by immigrants and 51% of the billion-dollar startups were founded by immigrants. While some companies seem to abuse H1bs I can honestly say that in my experience there is a shortage of good engineers, at least for the areas I work with (high-speed networking code, embedded processors, bootloader code, Linux kernel code, etc.). There are not enough Americans graduating from college with the degrees and skills needed to fill the gap, especially as the older engineers start to retire.
Like the above poster, we see far more foreign born applicants than native born. Unlike some companies which hire a huge number of H1b's who aren't all that skilled, my employer tries to be picky and hire good engineers and we jump at the chance to hire truly great engineers, regardless of race, sex, etc.
We are a country of immigrants. Immigrants help make this country great, bringing new ideas. Silicon Valley has always been a land of immigrants even as far back as the gold rush, where Chinese were brought in through San Francisco. My current employer, as were about half of my previous employers were founded by immigrants.
I say this as a native-born white guy who was born and raised in Silicon Valley. I work with a lot of very talented engineers from all over the world, including many from south-east Asia. In every engineering position I've held, I've been surrounded by "minorities" and am often the minority. Steve Bannon is a disgrace.