Something that really surprised me when I first published The Forgotten Colony

When I published The Forgotten Colony, I expected Ryker or Carver to be most people's favorite characters. After all, they're the most well-developed. I could also see Zach or Cora being favorites simply because they're perspective characters.

Then, people started to really like Mabel and Erik. This was very surprising to me, as they're both relatively small characters in the book. They don't have really, really recognizable voices the way Carver does in his scenes. However, I will admit that I really like Erik's backstory and the fact that he gets a robotic leg.

Why do you think this is? What makes Mabel and Erik likable characters?