Who's Lefsetz kidding?

Usually Bob Lefsetz's Lefsetz Letter is a fun read in the way that Rush Limbaugh is an entertainment program - just so long as you take everything with a grain of salt, you can admire Lefsetz's energy and passion about the music business.
But in his latest piece, he begs people to reply to his notion (though he's turned off the comments feature) that visuals are irrelevant to pop music. "Speaking of ears, isn’t that what music is made for? Ears, not eyes? Have we completely forgotten this?"
Funny thing is, he makes this claim in the context of a Mariah Carey CD.
Is there anyone out there who would argue that Mariah, at least of late in her career, has not used her image, and images of her body, to add to her sales? She's not Tool. She's not The Residents. She's not some anonymous camera-shy musician. She's a pop star in every sense of that term.
Maybe I'm just misunderstanding his thrust here, but can Lefsetz really be saying that he doesn't know what the cover of "50,000,000 Elvis Fans Can't Be Wrong" looks like, or that there is absolutely no value in the work of Klaus Voormann's Beatles covers, or the countless covers Hipgnosis made in the 70s added nothing to the listener's enjoyment or even understanding of the music inside?
The idea that music can only appeal to one of the human senses is preposterous.