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.
Well, except that in-universe in Star Trek,
there actually is
evidence which people might misinterpret as evidence of a cosmic
plan, such as that resulting from the activities of the Preservers and the ancient humanoids in TNG: The Chase.
Even Q alluded to the idea that humanity's evolution consisted of a progression that the Q were monitoring.
Otherwise, I agree with what you're saying.
Now that having been said, as a rule, it's more interesting dramatically when characters have inconsistent beliefs, than not, because it's a source of conflict.