You may be right but it's not high pay alone that draws in people from other industries. Standards must be relaxed to accept people from unconventional backgrounds. When conditions tighten, many of these people are simply not competitive enough to get another job. When it comes to aerospace, defense, academia, etc., opportunities are more scarce in those fields than in software the past few years also. It is this, not just the pay, that drives people to software.

I'm not saying people with odd backgrounds can't ever make it. But let's be clear, these are not usually hot shots who can simply get any vaguely technical job they want. They get into software because it is traditionally very accepting of uncredentialled or non-mainstream individuals. The framing you put forward makes it sound like the people committed to software are chumps who have to take what they're given, and these interlopers are the real geniuses who leave for greener pastures with ease. That simply isn't true.