Im not sure they tell you all the apps that are preinstalled per carrier before you buy a phone. Ive never seen a list. You're not wrong though.
Like paying to go to a movie theater doesn't mean you can choose to skip the ads before the show.
Probably still wouldn't dissuade most buyers, unfortunately.
I imagine advertising "Hey, User, remember that amazing Phone Model 1 you could buy for 600$? Now you can buy it with included spying software for your convenience, for the same amazing 600$ and we will earn 20 cents more from each deal! How cool is that, heh?! You want it too, right?!" :)