Though I’ve never read any of the Harry Potter books, this Jane Espenson essay in TNR¹ does a good job explaining why the story of a boy wizard is so captivating–he’s the Chosen One:
The Chosen One paradigm is the most positive, most comforting, most affirming metaphorical version of change, of growing up, that I can imagine.
And as Espenson argues, it’s also why Luke Skywalker and Buffy Summers have greater appeal than Star Trek and Battlestar Galactica; intricate worlds have their niche followings, but the Chosen One is a universal archetype. Keep that in mind during your next pitch meeting.
For my part, I’ve never been much interested in reading Harry Potter because I found the strikingly similar Books of Magic before Harry Potter was published (and I was a little old to get caught up in the first wave of Pottermania, though it’s pretty common for adults to read the books now). Besides, The Books of Magic also features everyone’s favorite trench coat wearing, chain smoking, itinerant magician. Honestly, who’s a cooler mentor: Dumbledore or John Constantine?
¹ A BtVS writer! In TNR! I nearly geeked-out.