Are film franchises money over art?

The Godfather trilogy is a great example of how a film franchise can and indeed should be done. Continuity? Yes. Do the second and third offerings challenge the original and each other in popularity? Yes. Could the second and third film stand on their own merit? Yes. Do we need a fourth installment? Greedily I would answer yes, but objectively I would ask "do we really need another one and risk diluting what is a perfect masterpiece of film making?" I don't doubt the lure of record box office profits a Godfather IV installment would generate would be irresistible to the production companies but, but, but, but... Surely there are too many arguments against disrupting in any way, shape or form what is a timeless example of majestic filmmaking. Which brings me to my question: which film franchise has been flogged to death in the name of profit and has lost all semblance to the original film that started the whole franchise? Which franchise has made you rage by spoiling what was a great film, it's sequel, perhaps even a great trilogy but now due to continuing churning out more and more senseless follow ups it's now nothing more than brainless entertainment?