There was a concern about folks losing the separate transformer, and a perception that a single device was better.

One interesting solution to this space was GRiD making their battery and power supply the same size and form-factor --- when one was working at a desk, to save space the battery could be removed and placed in a separate charger, while the cord from the power supply to the computer was removed, and it was then placed in the battery compartment and connected to the wall, powering the device.