As the home to the orca Tilikum, SeaWorld Orlando takes a real beating in the movie "Blackfish." The movie focuses on Tili and briefly mentions some of the park's other orcas and their shows, but it doesn't get into any real depth on anything other than Dawn Brancheau's death and other negative topics.
SeaWorld Orlando does, indeed, house Tili, who is part of a pod of seven orcas. However, the park has much more than just One Ocean (the orca show) and its other animal-related entertainment. They're a large part of what SeaWorld is all about, but its offerings go far beyond just animal shows. Check out the slideshow accompanying this article to see a more well-rounded view of what you'll find at the park.
I recommend seeing SeaWorld Orlando for yourself rather than simply judging it by what you see in a movie and what you hear in slanted media interviews. Yes, it's very true that the marine mammals live in small habitats as compared to the wild. That's true of any animals in captivity in zoos and aquariums. That doesn't necessarily mean that they can't have a good quality of life or that their lives in captivity can't contribute to the greater good.
Seeing Tili and the other orcas is one of my favorite parts of going to the park, but I enjoy all its other activities, too. Hopefully this slideshow will give you a more well-rounded view and inspire you to visit the park and judge it based on your own observations rather than what a movie, a writer, or anyone else tells you.