I think you're getting confused between DE and OS.
The reason you have different DEs is because of the OS you build, if you want a lightweight OS choose a lightweight theme. If you're not bothered by the OS size then go for what you think will work best with the Packages you're choosing to install.
The fact that there are many different distros to choose from is for user choice (freedom) if you had one distros for all you would end up paying for it as the source code would not be freely available.
As far as asking manufacturers to make Linux specific drivers...why? Linux is designed to be OOB (out of the box) usually if a driver isn't working correctly it's down to user error ( not always but it does happen more often than you think ) especially with the newer MOBOS, often all that's needed is to disable certain PNP options to allow the BIOS to handle everything.
It is a case of finding what works for you. If Windows doesn't work you're screwed whereas with Linux you have the option to try something else, it's a no brainer!
Also you would have to factor in a cost for all the specific drivers, this is why communities build their own.
It can be difficult to build a distros just the way you want it, take a look at the one I'm working on
https://tgigeeks.boards.net/thread/1400/new-atlemos-13-alpha
I'm constantly tinkering with it and it's still nowhere near being finished, when I chose the base it was just a txt version like UNIX and I had to add the UI and packages (some of which I've removed / replaced) to give an idea that what works on one system may not work so well on another. That's life! You just take what you've learned and try again.
