A farmer or construction worker (or at least one outside of Germany or any other culture famed for incessant rule following) only needs to watch the bomb squad guy rip a shell out of the ground with a shovel and no specific care given once before they realize it's best if they just do that damn job themselves and avoid the hassle.
Because that can happen. And if they know, it still can go wrong.
From TFA:
"In June 2010, three bomb-disposal experts in Göttingen, Germany, were killed by a 500kg American bomb found beneath the site of a new sports arena. "
https://www.theguardian.com/world/2010/jun/02/germany-bomb-w...
Do you apply this logic to surgery, engineering, etc.?
"The expert makes it look easy, therefore it must be easy."
Regardless, farmers across the EU pull thousands of tons of shells out of the ground every spring. They, as a demographic, have infinitely (because anything is infinitely more than zero) more experience than some out of touch office workers who read the official recommendations the local bomb squad writes up and screech about the fact that nobody follows them.
Frankly, the only out of touch person here is you - likely office worker who imagine that all farmers are irrational macho men. And someone who genuinely thinks that if some safety rules are skipped for comfort, then surely most will try to hit the bomb with random equipment to see whether it blows.
The farmer or backhoe operator or whatever does not typically know there is a shell or whatever there until after it's been hit with machinery. This is not the year 1100. People are generally not engaging the ground with hand tools. They are engaging it with buckets and implements that do their work in bulk. When you encounter anything man made it's usually only after you've moved it about. "Hey that's an odd looking rock, oh wait that's a shell". Once it's already been hit by your bucket or whatever the sensible thing to do is put it down somewhere far away, call it in, and keep doing whatever you were doing in the meantime.