I've heard this before, and on the surface seems like it's probably skewing a lot of the numbers (making the number of cable TV subscribers artificially higher than it otherwise would be).
At the same time, you, like many others, do have it hooked up to your TV, and you watch it at least occasionally. Despite the bundle being cheaper, you still are by all metrics a legit cable TV subscriber.
The big question is if it wasn't cheaper, would you still have cable TV? If it was $1 more to get TV vs just internet, would you do it, and at what point does it become too expensive?