“An audiophile buys a pair of speakers for $50K or $100K then asks what amps make them sound best.”
Well yes… an experienced one. Because this is the most effective and efficient approach. The speakers are the most important determinant of what you are going to hear.
The reason a speaker mfg doesn’t specify an amp is there is no “best sound” for all. Different people value different aspects of sound quality.
I have been an audiophile for fifty years and I assure you the sound qualities have changed very substantially over that time. My desires in the early1980’s were to make rock music slap me in the chest and play loud without distorting. My appreciation for sound quality now is leagues beyond those basic and unsophisticated requirements.
As a speaker manufacturer you want to attract the most potential buyers without putting any off. If you recommend an expensive amp then less wealth buyers will be intimidated… if you recommend cheap ones then well healed ones will suspect the sound quality… suggest both and people with other equipment not expecting to purchase a new amp will not buy it. It is a loose loose proposition. They typically offer general wpc recommendations.
Also, I have heard some absolutely ridiculous combinations of amp and speakers sound incredible. The Italian Viva tube amp (?4wpc)… powering huge Sound Lab Electrostatic Millenium-1 speakers. One of the most emotional (seductive) systems I have experienced.