You gotta remember that these ships were about 60 feet long, or about the length of a tractor-trailer truck. That and the food was foul as there was no refrigeration so if they got lost (and they got lost often) you ate spoiled food full of worms and maggots. Then you got scurvy because nobody really understood nutrition. And the work was back breaking under a commander who ruled as a god over your life. Most of these guys died unknown and forgotten.
Yea, life on the boats was awful, terrible. But think about this as well: life at sea for many of these men was better than a life on land back home.
why is this mutiny so famous? It's a funny story (how everyone seemed to find that tiny island!), but at first glance I thought this had something to do with Darwin's ship (which for some reason I thought was the Bounty, not as I just looked up the Beagle.
The Bounty was among the last real mutiny on the open seas in the age of sail. As such, it attracts a bit of nostalgia and "look back at the past" sort of storytelling. Within about 50 years of the Bounty, Wind driven ships were falling aside to steamboats. And, in my mind the real factor, the captain of the boat survived and made it back to tell his tale. That and the books became popular, then 4-5 movies were made which keeps the story alive.