Unless Linux is the default, it will never become significant in the mainstream. It is however thanks to improvements like these that OEMs can consider selling it pre-installed
Also I would to remind some here that the reason Linux can exist on the desktop today is because it is a very good way for Microsoft to get less antitrust fines. Otherwise the bootloaders would all be locked and there would be one or two devices that are unlocked.
This is also my main concern about the Qualcomm elite x: everybody is saying "hurray it will support Linux" but the actual cpu support was never really the issue. It's the boot process and device trees that is problematic and I don't see this being talked about enough. If it does not adhere to a standard device detection process like with Acpi via Arm System Ready we are cooked for arm laptops.
I don't really understand the argument of "people will use what ships." I don't think Linux is great at the out of box experience unless you count something more locked down. They great part about Linux is that it gives you a lot of control. These days you don't need to know all the details of how to use that control but I think Linux will become much more popular in the semi tech savvy type crowd. It is already wildly popular in tech.
For the same reasons people don't change their engines in their cars unless it's needed. For the same reason people don't install custom ROMs anymore. For the same reasons most people buy consoles instead of making their own computers.