I think it is more about finding a "perfect" fit, from the last hiring thread there was a job for which I thought I was a good fit except that I was lacking some prior experience in a specific ___domain i.e. anti-fraud, and that alone was the basis for not pursuing it further for the company.

Also this time, I see companies hiring "security engineers" with "Strong proficiency in Go or Scala". It is not like they are willing to offer much higher salaries for people who are both security engineers and full-stack software develpers, they just want it for the same market avg. salary ranges.