Many Blu-ray movies also give you a "digital copy" (as well as a DVD), so you can download it to devices, although personally, I would only want to do that if I had a long public transit commute or was on an airplane.
For your average TV show, I don't care that much and a download would suffice. But for great movies, especially beautifully shot classic films and/or films with great sound, I want it on my calibrated 55" screen and playing back through my multichannel sound system.
I think Apple's made a good step forward here, but Apple used to be the company that pushed "the best" and now they've become the company that pushes "good enough" but frequently at "the best" prices. Along with that, Apple pushes convenience over quality. What bothers me about this is that Apple seems to care far more about elegant case design than image or sound quality. As much as I love the industrial design of Apple's products, I would live with a lesser design to gain other performance improvements.
Of course, Apple could support both worlds, but they won't, so we'll never see an Apple laptop or desktop with a Blu-ray. For many people on this Forum, that's no problem, but if Apple doesn't want to include it, the least they can is support an external drive in the OS. But they won't either because (take your pick) they either believe that there's no future in physical media -or- they want to force their users to use iTunes or AppleTV.