It's the author's / developer's creation, their imagining of the of the plot and milieu, their story; so, yes there will always be their chosen ending.
Few, if any, plots are immagined with multiple endings. The definition of good or bad endings is subjective and the author's choice. The reader / player may reassign the adjectives applied to ending from their subjective point of view; however, that will not change the narrative.
AVNs introduce a choice element to the narrative form; at its basic these are primary (good) or alternate (bad) ending, as envisioned by the author.
Other paths need to be plausible branches from the path to the author's narrative destination and will naturally be shades of the primary leading towards the alternate ending.
Ultimately, the player of an AVN has no real choice; the end has been defined and unless a sandbox is provided and you stay in it you will always end at the author's choice of ending