Lets try to be objective, I honestly posted my opinions on objective terms. Kataang has so much indication, they have known each other since the beginning, they have had their nice moments, Aang likes Katara, Katara has shown jealous when Aang was with other girls. All Zutara is the desire of a fan base, which doesn't write for the show.
Everything it pointing towards Kataang, besides I would think Zutara fans would embrace being the underdog. I know what that is like, coming from New York, the home of the Super Bowl champion New York Giants.