It's important to realize that kernel-level code is significantly different than application or user level code.
The kernel of an operating system like Red Hat or Windows XP is primarily a software interface to hardware; a software-based machine virtualizer.
Everything that happens on your PC, for example, does so either directly or indirectly through the kernel.
As you would infer from such a proclamation, this means the kernel must be as efficient, stable, performant, secure, reliable, predictable as
humanly possible. It follows that you will want to restrict the number of humans writing the kernel of an operating system to a select group of highly skilled (and narrowly focused) software engineers who are very well-versed in both the art of machine
level programming and the craftmanship of enabling a machine to be programmable.
I think your right the bar for kernel level code is very high, as it should be.
I know lots of people have managed to add patches to the linux kernel, in fact, its soon almost as a badge of honour to have a patch accepted by a contributor, it says a lot about you programming skills.
The video was interesting, but i felt it raised questions that we've moved on from, as a community, like writing apps for various distos, as lots of companies have sucessfuly written solutions that work on all distros. Look at adobe reader, java. There is usually
some set up but its distro independant. Or just staticly compile packages.
Also with package management, most distros use either apt or yum so keeping up to date or installing new packages is as easy as typing yum update, or yum install <package a>.