This is just a different time. Blu Ray is never going to even come close to the success that DVD had. The 4K discs (along with other legacy devices) will keep optical media afloat for quite a while, however it's not going to be the primary source of media for the majority of people. Digital distribution is very convenient and the 1080p streams are of an excellent quality. The uncompressed DTS and Dolby HD streams do sound great... But guess what? So does the core DTS and AC3 5.1 tracks that are standard with any streamed HD movie. Most of my digital collection has DTS 5.1 and I'm more than happy with it, despite the fact that I am very picky when it comes to A/V quality.
I was a Blu Ray fan at first, but after dealing with the copy protection BS, constant mandatory player updates, digital copy woes, and everything else, I've jumped ship to streaming services and other forms of digital media.
It certainly doesn't help that Hollywood went so far with the copy protection on Blu Ray discs. It's annoying when the customers are forced to update their players so frequently, not to mention how difficult it is to watch the $20 movie you just bought on all your devices. The "digital copy" idea was sound, however in practice it doesn't work very well at all. With a service like Netflix or even Comcast's Xfinity TV, I can watch the same high-quality content across all my devices on command.