You're ignoring the impact of market share. Antitrust law is premised on the idea that we respect free competition unless a single party (or a cartel of parties) controls enough market share that we can no longer grant them the same freedom we grant other competitors. This is true even if it is not a 100% monopoly, but sufficiently lopsided that a party controls the market almost completely. I suppose the best analogy here might be if Apple was Microsoft Windows, circa late 90s; yes, there were alternative platforms available, but Microsoft's command of market share that it wasn't simply feasible to tell parties to develop on separate platforms. Now; as to if this is appropriate here, I'm not sure Apple has sufficient market share for us to be concerned.

You have your facts wrong. HP knew what the PIs were going to do and authorized them to do it anyway. A senior member of HP's general counsel, and, in fact, their director of ethics, was told of what the PIs planned, did "about an hour's worth of online research" on the legality of pretexting, and signed off on the plan. http://schakowsky.house.gov/index.php?option=com_content&task=view&id=444&Itemid=17