Basically, the article argues that Great Britain evolved as more of a collectivist, "socialist" society, whereas America is rooted in the tradition of individualism. 

Isn't this a bit of a semantics game, though?  If the band were called "Mick Jagger and the Stones" instead of "The Rolling Stones", would it make a difference?  In other words, if we forget about "Bands" vs. "Solo artists" and merely rank the list of "Musical acts", would the British still come out on top?

By the way, I have never heard of this "Donovan" #2 British solo artist.  What in the world?

He was Britain's version of Bob Dylan.  Hurdy Gurdy Man, They Call Him Mellow Yellow, Season of the Witch were his top hits among others.

I thought the article makes poignant sense.  Britain has more collectivist tendencies and America has always focused on individuals who were able to stand out in a crowd.  Perhaps it's easier for the American music industry to hype individuals over their bands?  Jim Morrison for the Doors, Jimi Hendrix, Bruce Springsteen, and Bob Seger are the best examples of front men who gained more attention than their highly talented bands.  Some British examples would be Ian Anderson from Jethro Tull and perhaps Eric Burdon and the Animals.