First, a definition:
genre - a class or category of artistic endeavor having a particular form, content, technique, or the like.
Second, an anecdote: There are many in the picture making world who abide by strict definitions of various picture making genres - landscape, portrait, street, still life, flora, fauna, wildlife, avain and the like - and they do not abide with any infringement or derivation from those definitions. As an example, on a couple of nature photography forums / sites on which I formerly posted pictures, each category / genre had strict guidelines for what could be posted on each genre category.
I primarily posted pictures on the Landscape forum where the pictures had to be of the nature world without any signs of humankind - no trails, paths, wakes in water, entrails in sky or structures of any kind or similar infringements on the purity of the landscape genre. Any landscape pictures with evidence of any of non-qualifing non-natural elements had to be posted in the Man and Nature forum. And so it went in other genre galleries. No birds in the Wildlife forum, only in Avian forum. Etc., etc., etc.
Each forum had an administrator / moderator (or two) who was charged with keeping things pure. I managed to cause quite a kerfuffle on the Flora forum when I began to post pictures of flowers which I made on a scanner (see above flower picture), aka: scanner photography. The proverbial shit it the fan in a big way. The flora nazis came out in force and comments ranged from the simple "that's not photography" to "the pictures are an insult to true flora photographers who go out into the field with all their gear (scrims, diffusers, reflectors, wind breaks, strobes, etc.) and their expertise."
On the back-channel discourse - moderator forum (not visible to public - the flora moderators, who had devolved into the photography equivalent of the soup nazi, became so incensed that the flora forum would include scanner pictures that they left the site to form their own "pure" flora site.
In any event, on the subject of the still life genre, photography division, the traditional (some might say "pure") definition of that genre has been pictures which depict an arrangement, preferably arranged by the picture maker, of inanimate objects. In my commercial picture making career, still life was a large part of my picturing making activity (see above Duquesne Light picture) to include products and food. And, yes indeed, I arranged all of the inanimate objects and my skill in doing so was highly regarded and highly compensated.
So, when I received a notice for submissions to the Art of Still Life juried exhibition, I submitted a traditional still life picture. That picture was one part found - the bowl with edible items - and one part made - I placed the bowl on a selected tray and determined the light used in making the picture. As mentioned previously, it was juried into the exhibition.
However, due to the number of submissions and eventual selections of pictures which were outside of the traditional definition of the still life genre - dresser top tableau, discarded roadside objects, and the like - a qualifier phrase, Marvelous Things, was added to the exhibition title. I was surprised by this development but was in no way dismayed.
In preparation for this entry, I looked around the web for still life pictures and, lo and behold, I discovered many examples of pictures labeled as still life that were considerably beyond the tradition definition thereof (see one example HERE).
Much of my current still life work is of found (see above kitchen sink picture) visually pleasing arrangements of inanimate objects as opposed to made arrangements. Nevertheless, virtually all of those pictures evidence the look of traditional made arrangement still life pictures. In some, I have moved an object into a more harmonious placement within the arrangement but, despite that intervention, the arrangements are truly found. Consequently, I have no issue with calling the pictures still life pictures in the traditional / pure definition of the genre.
All of that written, I am not a still life nazi, purity wise. And, I truly don't understand the fuss about purity of genre that so many hold so close to their picture making bosom.