Because those who make that choice believe (or have data proving it, but my feeling is that usually they just believe) that users are too dumb to understand.
That's a real problem in many situations: users are often under-estimated (they are also often dumb, which doesn't help).
They should invent a measurement unit for trackpads/touchpads, whatever we call them. Then a grade 5 touchpad will be immediately perceived as better than a grade 4 one. Or Basic, Business, Elite. Marketing teams are good at that.
I can get on board with that. Just some kind of language to describe a touchpad in marketing material. Without it, it is hard to see, without living with it, how a touch pad differs across two or more devices. I tend to think of touchpads as Mac touch pads and non-touch pads. Even though that is wrong.
That's a real problem in many situations: users are often under-estimated (they are also often dumb, which doesn't help).