There is no way that you can lump all humans together, just like you can't lump all animals together. This penguin is very loyal, but there are other animals who would attack their owners in a heartbeat. The same can be said for humans and their relationships. We can learn from good examples in the animal and human worlds.
There are some humans that are exceptionally loyal, sticking with a loved one through horrendous injuries or ailments or financial disaster. Some humans are loyal to more than a single individual. Medical personnel and rescue workers sometimes qualify for this. And then some folks who think they're being loyal actually qualify as mentally unbalanced -- in the sense that they are allowing one aspect of their lives to overwhelm facts and realities.
There are plenty of examples of humans showing this same type of loyalty to others. Think of people who stand by their spouses who have debilitating diseases and don't even know who they are. Or people who risk their lives by fighting foreign wars because of loyalty to their country.
While stories of Dindim the penguin and other heart warming animal and human interactions are numerous and fascinating, it is sometimes difficult to find a similar story that just involves humans. Humans have the capacity to be as loyal as these anecdotal animals but, often times, our brain's higher functioning gets in the way. Humans have the ability to weigh the pros and cons of any interaction and relationship with a depth that animals cannot and, it seems, that this has caused us to be more self serving than loyal.