I prefer using the keyboard nub on my ThinkPad myself, and have the touchpad disabled. If I'm typing, it's easier to use a nub. If I'm not typing, then I'd probably prefer a touchscreen for more accuracy.
As long whatever I'm doing doesn't require precise movements, then a touchscreen is good enough, and easier to use. If it's something harder to touch with big fingers (say position in code), then I'd probably rather use arrow keys anyways.
I’ve used one on other people’s macbooks.
I think my objection is mostly aesthetic. It just seems so gaudy and excessive or something along those lines.
Does it turn you off because you feel that you would touch it whilst typing, or is it something else?