The issue with google voice is different, Google voice is not a direct competitor to apple's operating system. They would be intentionally preventing someone from using software just to harm a competitor, rather than compete. Thats a big no no. The difference is the android app provides only information about android, a direct competitor. The other apps that feature android among other tech info is different, because they would be censoring all of the other information.
And yes, obviously apple is a publicly traded company. You say it like no one knows it. However, apple is owned by people, as opposed to the internet which is free. So in that regard, it would still be public vs private. I can go out and walk in a public street. I can't just walk into apples headquarters, regardless of whether or not it is publicly traded