^Fixed that for you
I agree that EqualizerAPO, REW, MSO and madVR are great; but if a PC can't even playback all of the lossless audio channels present on a 4k UHD Bluray, when an AVR can, what is the point of all the extra hassle?
My understanding is that it is the intended purpose of HDMI and HDCP to ensure that the end user never has easy access to decoded, lossless, digital audio signals (to make piracy more difficult). I think licensing and maybe compliance testing are required for devices that decode HDMI, Dolby or DTS data. I don't know why sound cards and audio interfaces that include the necessary licenses and software (perhaps restricted to analogue output) seem not to be available for purchase? Do the relavent bodies refuse to license them or is it just considered too niche? Or perhaps they are available but only at prices that limit access to professional content creators?
Is audio data treated more strictly than video? In a PC environment is there anything to prevent you from pressing print screen and grabbing full resolution stills from a bluray, or intercepting and capturing DVI-D signals sent to a monitor without HDCP? Perhaps compliant software prevents this?