Actually, I'm pointing out the progression of philosophies debated and adopted by characters in-universe. If "nature's plan" is nonsense to you, take it up with Troi, Phlox, et al.
Just as Trek canon itself lacks consistency, so do in-universe philosophies. "Nature's plan" is a highly unscientific concept. It is in fact very close to creationism, which is basically a religious concept, and yet, in "Who Watches the Watchers" Picard dismisses religion almost with disgust.