That's how the market works. If you are Google or Facebook and you need 10000 more engineers, just pay enough to attract them. You'll get them from lower paying companies, which in turn will raise their salaries as well (but not as much), and so on. At the end of the chain, the companies which are the lowest paying and cannot hire anyone anymore will simply remove those positions. In time, more and more people will train to be software engineers, and salaries will shrink.