I read this several years ago in Robert McKee's classic Story and I've thought about it often. I had never thought of characters that way, but I find I agree. Because when a character resonates with me, it's not just because they seem real. It's often because I recognize something I value in them.
In Frozen, I love Olaf's optimism that a snowman can survive in summer and Anna's chutzpah to throw a snowball and a snow monster or leap off a cliff. In Pride and Prejudice I love Elizabeth's determination to wait for love and her strength to be counter-culture. In Heist Society I love Kat's fierce family loyalty.
What value does your main character represent that you think will resonate with readers?