The reasoning for this is the commoditization of software hiring. The idea is to target the median of the bell curve, to lower risks and costs associated with hiring. This targets the greatest quantity of developers in a moment, but it also means the people who play it safe, follow popular trends, and don’t take any risks on product improvements.
To think about it another way the idea is to create mediocre software with mediocre developers because the software is thought to cost less than finding, hiring, and retaining top quality people.
