any time you kill an animal.
The bigger and more exotic they are, the bigger the thrill.
Now, some people have a real problem with people who enjoy killing because of the thrill it gives them, and if they were killing just to kill and leaving carcasses scattered around the globe, I would have a problem with that too.
However, there are many reasons to hunt, and the animals are used in these cases.
A friend of mine who was a guide in Africa for many years told me that the people there use every last part of the animal. Nothing goes to waste. So, contrary to what some people seem to believe about these African trophy hunts, the animal dies for a noble cause.
GOVT regulations keep hunters from taking the meat home. Every hunter wants to eat their kill. Most of them get that chance, although they don't get more than a meal or two from it usually. The rest goes to the locals.
Further, as I have explained several times on here recently, hunting of any animal as sanctioned by a government is almost always one of the best things that can happen to the survival of that species. Sustainable hunting is a wonderful thing.
One last thing, these animals usually die faster and more humanely at the hands of a hunter than they would have out in the cruel and unforgiving wild. I don't know any hunters who don't have a respect for the animal and don't want a clean and fast kill.