You must be a physicist. Real world amp building is a catalog of compromises. Some cans have very demanding impedance profiles, and there are amps which are better suited to those types of cans.
And I echo Purk's statement. Although this may not be what he was trying to say, "wire with gain" sounds like the "accuracy" school of thought -- that is certainly not the only school of thought, and just because you don't fall in with these other schools does not mean amp builders won't still cater to them.