1. Ready made episodes
This is simple – every single chapter of the Harry Potter franchise has something going on, be it the introduction of Harry to the wizarding world, or the Yule Ball, each chapter has a beginning, middle, end, and sometimes even a cliffhanger! Could it be any easier for producers?!
I'm the last person in the world that wants to put a downer on anything Harry Potter, but there was SO MUCH missing from the films, that I can barely watch them now without immediately rushing off to read the books and get the full story again! The sheer complexity of the books would have translated much more clearly to the smaller screen, where we could have grown to learn Hogwarts and it's staff and students over a more gradual and all-encompassing period of time on television.
In the same vain, each of Queen Rowling's characters are so complex and compelling that all of them could easily have a series to themselves. I would personally love to watch the evolution of Weasley's Wizard Wheezes, or the beautiful and highly underrated love story between Bill and Fleur. And while on the subject of characters, do I even need to mention that Peeves would need to have a series to himself, just to make up for his shocking lack of appearance in the films?! Which leads me onto my next point...
4. Endless spinoff possibilities
Not only would every chapter of Harry Potter be the perfect episode, giving us a grand total of 199 episodes (that I'm sure we could expand into an even 200), but we would also have countless opportunities for spin-offs with the lesser known storylines of characters we don't really get to see... And not to mention the Marauders generation, and then the post-battle generation, and the generation that feature in the epilogue! The possibilities are truly limitless, if only television would take over and expand our magical world into another 200+ hours of wizarding perfection!
So, in conclusion, I submit that we embrace the Harry Potter movie franchise while we can, because it's only a matter of time before all our minds are blown with an epic retelling in TV form!