I, too, agree AND disagree. I see both sides.
However, let me make a point based upon my playing experience.
First of all, I've never made it "big" nor played in a band that made it "big." So my views of success here are somewhat limited, as I'm sure some think there is no success without making it "big."
I played in several bands, but there were only four of them in which we were seriously trying to do or become something (not counting a cover band I played with in the middle 70s that was on the road on a night-club circuit). Of those 4, 2 were successful in that we NEVER hurt for gigs and actually had people who kept track of our schedules and followed us around. I quit one of those bands because the lead singer/guitar player was more of an entertainer instead of a musician, was almost always drunk and even made up words to hit songs when he couldn't remember all of them. You couldn't get him to play something "as it was written" for love nor money. But boy, we always had gigs and were very popular in our area, even was a local "front" band for a big name country concert at one point.
The other "succesful" band I played in was my own, just three of us (all music majors together in college) who played what-ever and where-ever we could get gigs, and could have played much more than we did. We did covers only, and just put ourselves into the music with our own style...
The 2 that weren't successful? Made up mostly of "perfectionist" type of guys who only seemed to want to be exact copies of what we covered... and neither band really got off the ground before breaking up.
So, I think this debate could rage on forever... and never come to an agreement!
Bill