The problem is that you get into diminishing returns. DVD is definitely better than VHS, but if the movie is engrossing then you rarely notice how crappy VHS looks on a smallish screen. Even SD iPlayer streams are watchable on a projector, although you do notice pixelation at times. The thing that killed VHS wasn't really the picture quality though, it was the convenience. DVDs are smaller to store, can be played on laptops and portable players as well as big TVs, don't need rewinding, don't get tangled in the machine, and so on. BD is less convenient. Most computers still don't have BD drives, they take ages to load, they're more effort if you want to rip them to play on a tablet, and so on. Their only advantage is the quality and, unlike DVD vs VHS, they're a step backwards in almost every other regard, which makes them less of an obvious upgrade.