It's not only about memory size, but the speed of processing too. Higher level protocols would signal an error, and require a retransmission until no error is

It's not only about memory size, but the speed of processing too. Higher level protocols would signal an error, and require a retransmission until no error is detected. However, "majority rule" does indeed sound like an error checking mechanism designed by a non-engineer (or non-mathematician) commitee.