The argument is that farmers (or anyone else) actually do have a right to protect/defend their property (livestock are property). So when the government says that you can't protect your property if the thing killing it is a wolf, then farmers get very frustrated because they feel like their freedom/rights have been controlled or taken away from the government.

To put the farmer's perspective another way:

Everyone has a right to self-defense if you are being harmed. But imagine if the government says "actually, if the person harming you has blonde hair, then you can't defend yourself because we are protecting people with blonde hair right now. But don't worry we will make it worth your while if you just let the blonde person hurt you."

I know this sounds like a crazy example, but if you have ever spent time around farmers who deal with this issue, it feels exactly as crazy to them.