HN seems to think PMs have a lot more power at Microsoft or large corps than they actually do. I assure you, a bunch of this stuff just comes top down because some VP's million dollar bonus rides on it.
The mandate to identify ways to increase profit comes from above, and it is the PMs (through marketing/research/developers) that come up with ways to satisfy these requirements.
And failure to meet these requirements means a bad review and a chance of being laid off.
Trust the HN crowd to know.