It's my understanding that Antarctica is much harsher than the Arctic areas where the Inuit live. There's no permanently terrestrial life, so no caribou to hunt, and no foxes, hares, or ptarmigans to serve as a last ditch resort. There's plenty of sea life during the summer, but if you don't get a huge amount of meat stored by winter, you're pretty much boned unless you can find a penguin flock.
Even then, though, you have to be really careful about not over-harvesting. Humans drove the Great Auk to extinction, if the Inuit accidentally make the Emperor and other penguins go the same way they're dead.