Do you honestly think the demand for software engineers will go down in the next 10-20 years?
Companies like Google and Facebook, large, profitable enterprises that can cherry-pick the best college graduates from the best schools and invest in long-term development, are one thing. But unprofitable, angel and venture-backed startups that are pressured to grow (and that includes headcount) are another thing.
A lot of the salary froth at the entry-level end of the market is being driven by the latter, not the former. This has nothing to do with the long-term demand for skilled, experienced software engineers.