It has nothing to do with me. The market decided all that before I was born. Seems that divorcing amplification from speakers allowed them to sell three times as much kit, and for that to work the industry adopted the voltage source, low source impedance paradigm with amplification. McIntosh's use of autoformers is the exception, not the rule, and not based on technical merit in the modern hifi realm. Just trying to explain to you why your devotion to anachronistic tech is misplaced.
The whole point of manipulating the load using passive network components (for crossovers, notch filters, bsc compensation, zobels) is to manipulate the power going to the drivers to optimize the acoustic response, and done assuming low source impedance. When that high output impedance McIntosh is thrown into the mix, it will try to deliver the same power regardless of the load. That means the freq around crossovers are not attenuated, and that notch filter now results in a peak instead of a cut. And linearity goes out the window.