It's not.
Your hardware has incompatible drivers, or your software is badly written.
Recently I brought a slightly older MB (new). It doesn't support windows 10, all the drivers are for 7 - and it didn't work until I turned off the HDMI audio, because it didn't have compatible driver.
Now its sweet as. On my last machine I never had a problem, but then again, I used add on graphics and external sound.
If your machine has bugs, IMO, it'll be one of two things:
1) Software that doesn't share memory well.
2) Hardware with drivers that are not win10 compatible.
Neither of which have anything to do with microsofts coding of the OS.