When I was 10 years old, tinkering required going to the library, and if you couldn't find any Spectrum book there, the only tinkering left was LOAD "" or trying to understand what Timex 2068 manual was all about.
I also hardly tinkered until I got into programming classes later on the high school, and then it wasn't tinkering, my time spent with Timex, Amiga and MS-DOS was about coding, demoscene and games, not fixing the OS.
Tinkering and fun means different things to different people. That's okay. Your idea of fun wasn't to fix the OS -- mine was.
I went to the library in '97 and borrowed the Linux Bible, with a CD-ROM copy of Yggdrasil Plug'n'Play Linux that I installed on my 486, and the new world that opened up to me of being able to modify, tune and customize the entire OS to my liking with no restrictions was magic.
Today, I work as a Linux sysadmin and I have fun at work. Other people of the same persuasion are the ones who maintain Linux distributions or contribute to the kernel today.
The point here is that if a kid finds it fun and creative to futz around with "fixing the OS" then let them -- not only is it its own reward, it might lead somewhere. Don't say "no, this isn't fun in my opinion and you shouldn't have to do it".
Then accept reality that you have 0 control. You will always be unhappy with whatever setup. Its not realistic that 3rd party will replicate your mind state about how your OS should look like.
I already gave up on "The Year of Desktop Linux" around the time Windows 7 came out, and VMWare/Virtual Box were good enough to run it.
And in what concerns WebOS, Android and ChromeOS, if it is Linux kernel, BSD, Fuchsia or whatever powering Chrome and Android Runtime, I couldn't care less.
