Orcas are not true whales but part of the dolphin family. They have a similar need for play to their dolphin cousins….. though a lot more intimidating when you consider they weigh up to 6 metric tons.
Orcas are highly social and removing them from their pod subjects them to severe psychological trauma, equivalent to keeping a human in extended solitary confinement. Orcas held in captivity develop pathologies, such as dorsal fin collapse in 80 to 90 percent of captive males, and only survive about 20 years compared to up to 80 years for females and 60 years for males in the wild. Captives tend to act aggressively towards themselves, their tankmates, and humans. The 2010 death of SeaWorld Trainer Dawn Brancheau is one of several recorded fatal attacks by orcas in captivity.
Fatality at Sea World (note the collapsed dorsal fin)
Ocean Adventure Subic Bay, Philippines March 2010
Southern California Theme Park (collapsed dorsal fin again)
These are just 3 recorded incidents. The shows are big money spinners and theme parks will not stop subjecting orcas to captivity unless the weight of public opinion turns against them and attendance figures fall.