Well, it can be appealing in one of two ways, depending on whether you’re interested in age progression from a destructive or constructive viewpoint. (For more on what I mean by constructive and destructive, go read this article by me at the NCMC). Like many fetishes, AP can be used both as a reward and as a punishment, and so it’s appeal can differ depending on who you ask.
Some people simply are attracted to older men (myself included). For these readers, the simple act of growing older gives them an erotic thrill, and they consider AP a constructive transformation, moving them closer to their personal ideal. In my mind, the authors at the furthest end of this spectrum would be Mark Gordon and Rik. The appeal lies the appreciation of the maturity and respect growing older tends to engender. There is a desire in these works for a simpler, more comfortable life that growing older tends to give someone. That said, constructive age progression tales are vastly outnumbered by destructive age progression tales.
Much more often, the act of aging is treated negatively, often in revenge stories, where the act of aging is instead treated as a destruction of a young man’s potential life. It is still possible to have AP presented destructively and still have an appreciation for the older erotic, but this is generally tempered by a certain amount of fear and regret as the subject’s assumed time of death leaps forward by decades. In these stories, the erotic transforms into a sadistic/masochistic force, depending on the perspective of the story.
All of that said, the tone of your initial question implied a certain skepticism towards AP at all, which is fine too. Some people don’t find older men attractive–fair enough, but this is a basic summary of the motivations I perceive behind the fetish.
Bracken's Corner 