let me try to explain the rationale behind the TN rule as I see it.
First off, I agree that the rule is inconsistently applied, but not because there is no consistent rule, but because some pictures simply slip through the net. There are so many posts, and if nobody takes the time to report it, a post in violation of TOS may well be overlooked and in the meantime draw many points and comments, simply because it happens to be a good photo.
So let’s all try to actually use that “Report” button more frequently, to keep possible frustration down.
As to the rule: forget about “nature” in the broad sense (that would also include homo sapiens by-the-by!). Instead, TN is about wildlife and natural phenomena that focus on that part of nature that came into being without human purpose or intent behind it.
So no animals or plants specifically bred for human purposes. Therefore no cultivated fruit or veggies, no dogs, sheep, horses, no feral animals that also were bred and just happened to have escaped into the wilderness after having been changed purposefully according to human needs.
On the other hand, most zoo animals are OK as there is that conservation aspect; zoo animals may also be bred, but obviously not to produce more milk/wool whatever (i.e. human purposes in the narrow sense), but to preserve these animals as they occur/have occurred in the wild.
Similarly, a wildflower that has not been bred/changed for human purposes but is propagated to show an exotic species/for conservation purposes is also OK, even if it happens to grow in a botanical garden.
Star constellations, stone formations etc. are OK as they occur without human hand.
Destruction of nature by human impact I believe is also OK as the main theme is the loss of wilderness, not the human hand in to (two sides of one coin, but usually it is pretty clear what the focus is on).
If your main focus in an image is a cultivated plant (lemon, papaya, cammelia) then the inactivation was according to TOS.
Obviously cultivated plants are also an attractive part of nature, as well as many adorable pets and farm animals.
However, I believe most TN members appreciate that the owner of this site decided to focus on the wildlife aspect of nature, which the Terms of Service and previous threads on the matter reflect.
For the other part of nature shots, the sister-site TrekLense is an option which has not similarly restrictive TOS.
Why not post a link in the TN forum so that interested TN members will know about your TL post of the “cultivated” variety?