Engineers who work for companies like Google, Facebook, Amazon, Microsoft... They aren't getting paid for engineering. They're getting paid to increase employee head count which gives corporations political leverage. Also, they don't want smart people to be thinking about the economic system in an objective way - Hiring smart people and giving them massive salaries and bonuses is a good way to keep those people focused on ideas which are aligned with the existing corporation-friendly political order.
It's not just those four, rando startups have started to do it as well.
It's the third time in my career that I see a company making the developer head count jump from 10 to 100 only to ask all the newbies to rewrite the software from scratch in the most disorganized manner possible.
I'm becoming allergic of rewrites, but I'm pretty sure that I'll land into another one if I switch companies again.