They do, if that's what it takes to keep the qualities that make Linux different. If it turns itself into a shitty Windows clone, then one might as well use the original.
No, on the desktop, they absolutely do not. It may please a tiny subset of people who understand what the kernel is and read patch notes, but no one else.
It works fine for members of my family and extended family that have Ubuntu installs on Intel GPUs. Light gaming and more importantly, hardware accelerated YouTube works just fine.
I'd be willing to bet that most people really only want windows to appear quickly, scrolling in web pages to work well, and to watch videos online.
Lots of casual gaming has moved to mobile, and never left the consoles. Hardcore gaming -- not most people.
I used to think like you too. But spending around 3 to 4 hours a month (that's being very modest) trying to fix video tearing, hibernation issues, wifi issues etc. after every kernel release is a pain that I won't endure for long.
That sounds like someone who has no idea what they are talking about. The open source drivers are a bit buggy. The binary drivers work just fine on Linux. Their performance in games is lower compared to Windows, but that is the case on OSX too.
Nothing to do with Windows and OSX being bundled with the hardware /s