Yeah, I remember those machines and did even see one used in person once.
Aside from any Apple magic and all the associated style factors, I think technology was just not ready then; they were just a laptop with a reversible screen, which was too heavy and bulky to be used in the ways people actually want to use a tablet rather than a laptop. You might have gotten two hours of battery life, for the first week of its life. And the stylus wasn't exactly inspiring either - it smacked more of a way to easily translate mouse-driven software than the best way to interact with the device. That's a lot more obvious in hindsight, of course.
Aside from any Apple magic and all the associated style factors, I think technology was just not ready then; they were just a laptop with a reversible screen, which was too heavy and bulky to be used in the ways people actually want to use a tablet rather than a laptop. You might have gotten two hours of battery life, for the first week of its life. And the stylus wasn't exactly inspiring either - it smacked more of a way to easily translate mouse-driven software than the best way to interact with the device. That's a lot more obvious in hindsight, of course.