The pinched wires, I would suppose, are on the wiring between the battery and the connector to the PCB, which could be subject to being moved and not fixed in location and routing. More like the design of a portable phone battery than a cell phone. Only fuses right at the place where the wiring enters the battery, or inside the battery casing, would be total protection.
However, they add another layer of risk in the failure flowchart, and engineers could have decided the cost outweighed the benefit.
Of course, this is all guessing, that could be halted by one decent picture of an open unit.