Vista's market share is a rounding error - it never overtook XP. Today XP adoption is still almost 5x higher. They could have mentioned it, but XP support is by far what people care about.
My understanding is basically vista was a huge step forward in the security and stability of the OS, but those changes made traditional backwards compat harder to maintain (eg old software was more likely to break), and the driver model changes made the entire windows driver system waaaaymore secure, at the cost of requiring either substantial rewrites (especially for the gpu drivers) or slow compat layers. After a couple of years drivers etc had settled down so performance horrors had been fixed, and more software was actually doing the right thing, but by then win7 was out.
Because of the problems with it people (incl oems) didn’t sell it :-/
> Vista felt incredibly half-baked, and no one I know kept it once Windows 7 became an option.
The family of my two best friends (which is like a family for myself too) is still using vista. It's fascinating how it felt like a giant beta test for win7
