The problem is that you are not dealing with professionals. Professionals work to make the song and the recording great, no matter what. This ego stupidity doesn't happen.
Just last month I watched a documentary on Big brother and the holding company. In relation to Janis Joplin, they'd disagree with you straightaway. As would John Lennon, who felt that Paul McCartney would try to "subconsciously sabotage" his great songs. And I think Keith Richards would too, when the subject of Brian Jones comes up. As would members of the original Mahavishnu Orchestra, Tony Iommi on Ozzy, Dee Dee Ramone on Tommy, Ian Paice and Jon Lord on Glenn Hughes and Tommy Bolin, Ginger Baker on Jack Bruce, Gene Simmons on Ace Frehley, Francis Rossi on John Coghlan and Alan Lancaster, Rick Wright on Roger Waters,
Jeff Beck on Keith Relf, Stevie Nicks on Lindsey Buckingham, Gene Clark on David Crosby, Steve Took on Marc Bolan, Brian Robertson on Phil Lynott, Brian Downey on Brian Robertson, Andy Summers and Stewart Copeland on Sting, Sam on Dave,
Noel Gallagher on Liam, Dave Davies on Ray, Brian McLean on Arthur Lee, Jean Jacques Burnel on Hugh Cornwell, Les McKeown on Eric Faulkner, Joe Zawinul and Wayne Shorter on Jaco Pastorious, Dennis DeYoung on Tommy Shaw, Mary Wilson on Diana Ross................I could fill 7 pages or more on the professionals for whom this ego stupidity most certainly did happen and those that got in the way of great songs happening. It's part of the constituent of popular music.....and human nature.