I have to agree with you!! You would actually need a 7 or 8 foot covered fence actually, Foxes not only can climb, they can jump a 5-foot fence with no problem.Sorry, but shooting the predators is protecting my livestock.
So if I had the birds in a 5' high fenced in field, and a fox jumped the fence and killed chickens, you'd be ok with killing the fox? Or would you expect one to spend $100's or even $1000's of dollars that they might not have to fortify the field further?
Thankfully I don't live in Europe, and have plenty of ammo.