According to Ricki C. on his Growing Old With Rock & Roll blog, Van caused rocker Bob Seger to forget his roots and put out MOR sludge which led him to make millions. Here’s most of his post:
Van Morrison has a lot to answer for in the Ricki C. Rock & Roll Universe. Don't get me wrong, I like Van Morrison, especially the early stuff. (Much like Woody Allen movies.) Gloria is, of course, a genius rock & roll song. Brown Eyed Girl was the theme song for my high-school majorette girlfriend (from social pariah to a majorette girlfriend in less than six months time, THAT'S what rock & roll could do for you in 1968 & 1969) and presently for my lovely wife Debbie. The Blowin' Your Mind album (that Brown Eyed Girl was taken from), Astral Weeks, and Moondance were all great discs.But then, as Van the Man started getting all Marin County-ized and laid-back along with the rest of his rock generation circa 1971-1972, he (and they) kinda lost me. Plus, worst of all, Morrison started to drag genuine rockers like Bob Seger along in his back-to-the-country, watered-down wake. It's hard to remember now - after Beautiful Loser, after Night Moves, after The Famous Final Scene, and especially after innumerable plays of Against The Wind on TV commercials hawking Chevy pick-up trucks during football games - that Seger was once a rocker at heart. I can remember watching Bob Seger & The Last Heard or The Bob Seger System rockin' little Columbus dive-bars like The Sugar Shack with tunes like Heavy Music and Lucifer from the mid-60's all through the early 70's.
(Plus it had to be tough for Seger to watch Glenn Frey - a snot-nosed little Detroit high-school kid Bob let hang around the studio while he recorded killer tunes like 2+2+? and Ramblin' Gamblin' Man - move to California, form The Eagles, and go right past Seger on the rock & roll success meter until Live Bullet broke big in 1976.)