There are some real ethical dilemmas in all of this. Lions are now being bred for trophy hunters to hunt down. So, in some respects its increasing the lion population and its funding the wildlife sanctuaries.
In the UK we breed grouse and other fowl with the express intention of shooting them for sport. I don't honestly see a difference between that and the breeding of lions for the same purpose in Africa. Perhaps we should be putting our own house in order before we go telling other countries what they can and can't do