I personally do. A "just works" configuration will be ideal for me. Anytime I install linux on a new computer, I find myself spending too much time tinkering with configuration settings to make basic things like adjusting keyboard brightness and volume control work with the respective keys.
You don't have to do any of that with a Framework and Ubunut/Pop. The only real thing to adjust was getting the fingerprint sensor working, which really was copy/pasting a script. Everything else worked perfectly out of the box.
You can fix the battery drain issue by changing one line in a config file. The issue is from how Intel chips handle hibernation w/ Linux, so not a Framework specific issue though.
I don't, and I suspect that people who would want Linux preinstalled don't have much experience in it, and being lost would hate it, badmouth it, and badmouth the company for making it an option. Installing Linux is quick and of trivial difficulty, and if you're afraid to do it you should probably work on that fear at a different time than when you're also breaking in a new computer.
I would say that installing Linux is like being able to tune your guitar or a chef being able to sharpen their knives, but it's an order of magnitude easier than either of those things.
Agree with sibling that maintaining preinstalled Linux is a good sign that all the guts and peripherals are compatible, although that might be a perverse incentive to use a bleeding edge kernel/distro to accommodate flashy hardware. If anything, they should install a boring LTS/Debian Stable, completely stock other than a custom wallpaper.
I want to know that the hardware will work with linux, and will continue to work with linux.
A pre-install option is just one way to advertise and convince the user that you've tested the hardware to work on linux
Yes. The linux market is extremely diverse. The sheer amount of distros and DEs is pretty good evidence of this. It doesn't even have to be different people.
For personal laptops/desktop I don't care if it's preinstalled for me or not since the very first boot is going straight into my usb installer since it's extremely unlikely that they checked all the boxes I will check (especially getting my LUKS passphrase correct!!). But for my wife or parent's laptop that's exactly what I want. If dad runs linux I can help him out a ton more, even SSHing into his machine to set things up or install updates, etc, but I'd prefer he be able to turn the thing on and connect it to his wifi and start using it without me having to be there.