Lawyers routinely resolve almost all of their work with nastygrams (sternly worded letters demanding that someone take action on behalf of their client).
Mostly because it usually works. A huge proportion of all people would get quite scared from that letter and comply, simply because it looks so threatening.
I'm curious about how common this is with big corporations?
My personal experience suggests it's ridiculously common. People who work in large corporations often feel that the way large corporations work is the only way to do business.
Because of that, they simply look at all the resources they require and conclude that since they require this, that there must be no other way of doing things.
This is why startups can succeed - large businesses are stuck inside the boxes of their own design.
Do they really think someone will be fooled by their demands which have no force behind them?