I think this is mentioned in the article. There's a shortage of talent, and there's a shortage of talent at the price I wish to pay. These, of course, are not the same thing. There's also the question of worker mobility native vs. visa-enabled.

I think the second part is the only real distinction: mobility. Nobody who owns real estate is going to relocate across the country for a 6 month contract.

As far level of compensation everybody in the US, including H1B workers, work according to US compensation ranges but are limited by visa sponsorship. Software developers tend to average about 2.2x or more than the average US income even in expensive urban areas. In cheap rural areas the difference is staggering. If these developers lack sufficient talent the problem isn't compensation. The problems are improper preparation and improper candidate selection. Increased compensation without controlling for preparation and selection will only provide perverse incentives to magnify the existing problem.