Take on the two lions

Two days in a row we get TORs about animals euthanized while their humans who may be to blame walk free. Yesterday a horse was shot after breaking a cannon bone in a race before the Preakness and TOR asked why they didn't shoot the jockey since he was also hurt, too Today a story out of Santiago got our attention when two lions were euthanized after they mauled a 20 year old who had jumped into their cage in an apparent suicide attempt. I don't quite get why they kill the lions, they are doing what they are born to do, kill weaker animals. That is like killing a cow for grazing or a cat for purring.
So the suicidal moron is now in some hospital and probably will get a Diane Sawyer type interview out of this yet the two lions who happened to be in the wrong place at the wrong time get killed. Makes sense