While this is true, I think this exposes the weaknesses of the interface in no uncertain terms. For example, holding down the left button while moving the pointer about (which can be used for 3D rotation or translation in SW) is cumbersome and quickly becomes painful on a track-pad.
Similar issues appear when using other applications, such as 2D drafting or electrical engineering design programs.
Getting away from that class of software, even using Excel is a pain. A mouse or trackball have what I am going to call a "static" relationship with the pointer. If I life my hand I can go back and touch the mouse or trackball and organically move the pointer. When you do the same with a track-pad you lose your reference point completely.
At home we have a Logitech keyboard with a track-pad to run the PC connected to our home theater system. I can't describe how cumbersome this feels when compared to connecting a trackball to the same rig. I've run the test with multiple visitors. I give them a lap desk and the keyboard. It's uncomfortable. I then connect a wireless thumb-operated trackball. Night and day. Not one person wants to go back to the track-pad once they experience this.
It's a bad interface. It also happens to be cheap and probably OK for people who just want hang out on Facebook and do menial tasks on the computer.
My take is computer designers have gotten lazy. Nobody wants to innovate when it comes to the hard stuff. Apple used to have physical trackballs on their laptops. Innovating past the track-pad requires someone to have the balls to say "Hey market, try this idea" and be willing to have it flop. That's why it isn't happening, track-pad are crap, but they are safe from a consumer acceptance perspective.
