Humus is not just soil, it is a community of living things. Organic matter is a breeding ground for many types of microbes, including bacteria and fungi which break down plant material, and for other microorganisms that help plants roots absorb necessary nutrients.
I agree with your analysis, but I disagree that cagers refers to an entire class of persons, all motor vehicle drivers. To me, and maybe I am not using the right definition, a cager is an @sshole motor vehicle driver.
Scramblers are the current craze in the custom bike scene, and now manfacturers are catching on too, with several releasing great-looking all-new scrambler models you can buy right off the showroom floor. But where did this style come from, and what really makes a scrambler different from other bikes anyway?