It's just not very useful to have a sound card for the vast majority of PC users, due to wireless headphones, integrated audio (especially on laptops), USB DACs with better driver support, HDMI audio on the HTPC side. You need to have very specific requirements and equipment for a sound card to be worth anything today.
I know a lot of people don't want to bother with all the driver headaches and extra cost for a subjective improvement to audio. It seems like a lot of the energy behind gaming headphones are to do virtual surround, another situation where there is not going to be any benefit to having a really nice stereo out solution.
So I feel for people with audio issues. Last year I was dealing with some of the regressions around DD Live or DTS Interactive/Connect for 5.1 surround sound, another oft-ignored part of the PC audio equation. There is no excuse for Microsoft not to test their OS with these cards at some point in the process. But I'm not surprised these issues cropped up, I'm not surprised they didn't catch it for a while, and I'm not surprised that there aren't too many people complaining because sound cards are obsolete for 90% of their use cases.