Why low resistance? If you biwire, the first thing the tweeter signal sees after the speaker terminals is a tweeter padding resistor, usually in the range of 2-5 ohms. The first thing the woofer signal sees is about 100 feet of (usually) smallish wire wound up to create an inductor with resistance typically 0.5 to 1.0 ohm.
Low resistance is touted because it is easy for people to understand (compared with capacitance/inductance).
