> "[…] and these interlopers are the real geniuses […]

This wasn’t the framing I was going for. My point was that industry boundaries are fluid and expand/contract as demand dictates. You’re correct that incentives are not all positive (pay, work life balance, perks), other industries contracting might force people to find work elsewhere.

All that said, I don’t think these people have “odd backgrounds”. I work in a math-heavy domain, so these backgrounds make as much sense as a traditional CS background, and I think these folks are just as likely to be retained in a crunch.