The seeds found in apples are bitter. Sounds like a natural defense against animals feasting on them. In addition, genetically, each seed will produce an apple tree which bears apples of a different variety. Naturally, each distinct variety would only exist as long as the lifespan of its tree of provenance.
Source: “Botany of Desire” by Michael Pollan
“In the case of the apple, the fruit nearly always falls far from the tree.”Michael Pollan in “Botany of Desire”