I feel like an Ogre at critique group when I have to tell people that they need to change something major or fundamental about their story in order to make it work. I remember well, how it felt to be told that my story had issues that would require major re-writes. I also anticipate getting the same feedback from someone more experienced than I am.
I've been reading and studying and working really hard on my craft, which makes me more "critical" on my critique group partners. But what I'm coming to understand is that writing is such hard work that no one has time for wasted effort. And by wasted effort, I don't mean writing a scene where your POV is head hopping, or is unclear. I don't mean writing a scene where your characters motivations are weak or implausible. Those are all part of learning to be a great writer. Those are all part of the 1,000,000 words that you have to write. When I talk about wasted effort, I'm talking about writing the same things over and over with minimal alterations and no strategy for creating a saleable novel.
I myself have put my first novel "under the bed" as they say. If it ever sees the light of day, it will be in a completely different format. It needs to be re-worked from beginning to end. There are scenes that can be salvaged, but much more work needs to go into it.
As one of my critique group partners pointed out "if it was easy every one would be doing it" I'm not sure that a lot of people get that.