In my neighborhood in Bryan TX (area population = 130,000+) they trapped a 300+ pound wild boar. That climate is favorable to many critters growing too big for public safety. Not everything needs to be shot, but a 500-pound gator doesn't need to be out where it can prey on farm animals and distracted ranchers.
There are times when you can't move 'em or there's no place to put 'em, and then the outcome is more permanent. The gator was lucky there was a refuge that stepped up to take him..