For a counterexample, consider Apple and how they try to restrict you to a single Apple ID. They want everything to be tied to a single person. Every service you use is tied to your Apple ID.
It just doesn't match the way that people use computers.
For example, I get my computer games and business software billed to the same card, and there's no easy way to change that.
Somehow the app store "helpfully" installed a baby monitor app that I use at home on my work computer.
We set up a Mac as build server in the office. It's shared by multiple people. I need to log in with my personal credentials to download software from the Mac App store.
My girlfriend bought an iPad for the kids to watch TV. It's shared by a couple of people. She had to log in with her Apple ID to set it up, and now her personal iMessages and emails are on it. It's stupid.
Some of these problems can be fixed, but it's really annoying.