Agreed, a lot of people don't understand how difficult farming truly is. I know I can't fully grasp all the trials farmers face just by tooling around in my backyard.
Strength in numbers is a big part of having something left to harvest, although interestingly, some animals are strongly averse to fresh manure. In talking to dairy farmers down the street who grow hundreds of acres of corn for feed, I learned they spread manure as much for deer repellent as for fertilizer. The math, interdisciplinary science, experience etc. that go into agriculture are staggering sometimes.