Is it just me or are fire types the king of X and Y now? Entei got Sacred Fire, Heatran is more powerful, Fire-types can't be burned, Talonflame is running around. And I thought it'd be fairies to steal the show.
Heatran got more popular because of the Metagame that is going on right now. Heatran is the only pokemon that can fully counter Genesect, 9 resistances, and more partners to gel their weaknesses with like Mandibuzz.