None of your points seem at all convincing to me. It's like you haven't used a good touchpad. If you say things like "Much quicker than dragging a pointer around everywhere", then your current touchpad sucks. If it ever feels like you're dragging the cursor around, then you're dealing with a touchpad that has inadequate sensitivity and precision that forces the cursor speed to be set unreasonably slow. Likewise for your complaint about zooming. A good touchpad is every bit as responsive as a touchscreen, and you're not blocking half the screen with your opaque hand.
And on top of the touchscreen offering almost no advantages over a truly good touchpad, Apple's touchpads have haptic feedback that isn't really possible with a laptop-sized touchscreen. They also support a wider array of multi-touch gestures than most touchscreen software can recognize, and that's before getting into third-party software that adds more gestures, such that touchpad gestures can replace about half of the keyboard shortcuts I use.
I use an MBP for work. If I had a macbook for my personal laptop, I'd still prefer touchscreen for all the use cases above. I wouldn't think I'm the only one either, but maybe I'm wrong.
I don't see what Apple gains by not at least offering it as an option. That way people who didn't want one wouldn't have to get it. I'd pay maybe $150 extra for it. I'd also bet it would outsell the non-touchscreens ten to one.
And on top of the touchscreen offering almost no advantages over a truly good touchpad, Apple's touchpads have haptic feedback that isn't really possible with a laptop-sized touchscreen. They also support a wider array of multi-touch gestures than most touchscreen software can recognize, and that's before getting into third-party software that adds more gestures, such that touchpad gestures can replace about half of the keyboard shortcuts I use.