You are right there is no technical reason why you can't but there are probably commercial and practical reasons. The number of people with gaming PCs is relat

You are right there is no technical reason why you can't but there are probably commercial and practical reasons. The number of people with gaming PCs is relatively small and the complexity of providing it to them might be quite high. I don't know what the availability of stable HEVC decoders is like or what the licensing cost for them is or the difficulty of integrating them with Silverlight or whatever it is that Netlix use. The Youtube trailer was probably VP9 not HEVC but was possibly using a higher bitrate that could effectively be downloaded rather than streamed for a short trailer. Basically the complexity of supporting the small group of gamers with the right PC's and 4K monitors was probably not worth it initially especially considering the backlash from customers who's PC's weren't fast enough. It is easier to launch on a set of known devices and then they can expand from there. I'm sure it will come.