About 4 years ago, my wife's grandfather gave me a nice lecture at Thanksgiving about feral hog management here in Texas. He went into great detail about identification of sows and not shooting them. The idea was that you wanted to preserve the population for future hunting and if you kill off the sows, you ruin your hunting.
Mind you, it had been since the 80s, probably early 80s since he last had a lease or hunted hogs. Where he did have a lease was not good hog habitat either.
No matter how I tried to explain to him that times had changed, he thought me the dolt for wanting to shoot sows.
The Brits don't have a crisis with their boar population at this time. It may take a while before they do. Until then, folks like the guy in the OP's Youtube video or folks like my wife's grandfather will vehemently oppose what they consider to be wrongful hunting or overhunting.
"If you look through your scope and see your shoe, aim higher." -- said to me by my 11 year old daughter before going out for hogs 8/13/2011
My Hunting Videos https://www.youtube.com/user/HornHillRange