I think you probably hit the nail on the head there. I mean sure, I might stop and bop along for five or ten minutes to a band - but I also acknowledge what they are, temporary entertainment. I'm not a local, so I'm not showing up to shows as part of my Friday night routine.
Instead, I'm looking for a bit of ambiance as I tour the Canadian pavilion, and if it happens to be between showtimes, I likely wouldn't swing back by. I can bet that most visitors fall in my camp. The shows enhance the world, and if they are truly, truly bad there will be backlash, but otherwise it will be considered personal taste as to whether you stand and watch or move on.
I have no problem with Epcot having cuts of longstanding entertainment to allow for a change in the line-up. Maybe I'll eat my words if it turns out these lumberjacks are some awful act that is just so beyond my wildest dreams of terrible. Likely I won't. I'll fall into a camp of, "it wasn't for me," or, "yes, I watched the whole show."