George,
You are not even addressing his statement. Class D can already drive low impedances.......1100 watts from the NC1200 and 1000 watts from the mono 1200AS1 (all at 2 ohms). Tons of high end manufacturers use class d in their subs and in their powered speakers. Certainly, there are those very very few super low impedance speakers that need a welding amp to drive them.
The switching speed of an amp and the type of output devices have little to do with power (so why are you bringing it up?). The Technics does not have super low impedance driving capability (300 watts a channel into 4 ohms and no mention of lower impedance capabilities). That amp converts all analog signals to 24/192 and then fools around with the signal in the digital domain before it changes PCM to PWM.....really a digital amp.
I was talking to someone at IcePower some time ago about them using GaN transistors. They said the engineers were looking at them because they are so efficient they can be used in serious high power amps with less heatsinking. The IceEdge chipset is capable of producing up to 7000 Watts. Imagine what that amp could drive! There is no reason class D cannot drive even super low impedances....but why? Since the number of amps that need drive below 2 ohms is super limited....they why would a manufacture bother? You need higher voltage rails, more capacitors, more output devices, larger circuit boards, more cost, etc. Also......all amps create more distortion as the impedance lowers......I have never seen a measurement of an amp that did not measure worse at 4 ohms compared to 8......and then 2 ohms is even worse. Why would you want to listen to more distortion? High efficiency speakers and reasonable impedances make sense.
BTW, this (link below) has been available for years. No one has made a serious version, that I know of.....2000 watts into 2 ohms.....is that enough power?! It has built in op amp, somewhat low gain and low input impedance.....so probably would never sound as good as the NC1200 tweaked to the max........but, shows what can be done. Look at the size of that 3000 watt switching supply you use with it Much more can be done with GaNs as they are so efficient.
https://www.hypex.nl/product/nc2k-oem/79