EDIT - Mikk - you beat me to the analogies! but your post wasn't there when I started
Here's an analogy of the situation.
Some games would only talk to a tracker that sounds like it's TIR. So freetrack talks to games "like TIR" to get around it.
Whether we think that it's a "rip off" or not is one thing - but
this situation would not exist if games accepted normal axis inputs for head tracking.
But of course,
NP would rather this situation exist, than compete against a cheap DIY system.... If you apply the same logic to joysticks, people could not make their own sticks (which I do), because games would ignore them.
If games accepted generic head axis inputs, and all head trackers used it, NP would have absolutely no legal avenue for pursuing the other trackers, which is why they don't want this to happen.
It is ethically wrong that games should only accept input from one brand of device. It costs the game developers nothing to allow generic axis inputs, and yet they are often disabled, which we have seen in the case of DCS:BS to be a direct result of NP requests. I suspect that there are more games with similar situations.
You can say "it's just business", which it most certainly is, but some of us actually respect our customers, and have their interests in mind when designing products.