Can somebody, anybody, quote the provision of law that states vendors have to allow outside access to their hardware? does that include all hardware then, car infotainment, kindles, Xbox, Steam, PlayStation's? No? I didn't think so. Because there isn't one. should there be, that is a different discussion
You are looking at this from the wrong premise. This is about using the market position and share to exclude and control.
Depending on the country, there are laws and regulations about that.