Don't know if this is definitive, but:

https://www.johndcook.com/powershell.html#:~:text=The%20core...

POSIX Korn shell, specifically, according to Wikipedia:

https://en.wikipedia.org/wiki/PowerShell#Grammar

so maybe it inherited 2>&1 from Korn shell, which in turn was POSIX.

But yeah, Powershell was not built purely to be a POSIX shell, but I thought it tried to be compatible where it made sense (hence the seeming clash of cultures).

Isn't that because of posix?

If you place a sports bet online, odds (!) are that it will run through tcl in its business logic. I may even have written some of it.

Engineers can definitely contribute to the problem too, in my experience.