More resistance is less load??

There are reasons that a speaker manufacturer might choose to design a loudspeaker with lower numerical impedances. Measurements at the amplifier, are just that measurements at the amplifier. Yes, it's true that those measurements might effect the sound downstream; but downstream, such as at the listening position, there might be measurements that suggest that there were other benefits that made foregoing better measurements at the amplifier worth it.

It's easier for a speaker manufacturer to get a steady impedance (which amongst other things increases the potential for frequency linearity) with lower impedances than higher numerical impedances.

Most of speakers that can provide wave form fidelity (time and phase accuracy) have lower impedances.