alt Hacker NewsOne of the reasons it’s very quiet is that you can only do what the company that provided it to you allows you to do with it. You can’t reinstall a fork of PlayStation OS, for instance. Sony won’t provide you the sources and the changes they made. If it was a GPLv3 OS, they would provide everything you need to build your own PlayStation OS.
If it were a GPLv3 OS, it's likely that they would have chosen something else.