Frantz, you make some very good points. However, I do think there is a strong case for some manufacturer's hard wiring their power cords. The loss in SQ that I believe is there with the typical amp/preamp or?? iec connection is IMO an issue. The current vogue for iec connections and the strong after market power cord industry is not going to be in favor of this, but I feel that we are loosing SQ because of it.
As far as I have read some manufacturers hardwired power cords to their equipment to avoid that people would use power cords that could degrade the sound quality of equipment, changing their intentions.
Anyway, nowadays most of them have power connectors because they want to export and power cords are a nuisance when you need certificates on cables and different power plugs according to country. Using a power connector allows them to have only one type of amplifier.