Because Flygon and Altaria are so dragon-like. It's not like I haven't mentioned them in the post or anything.
And Charizard wasn't Dragon for the same reason Gyarados wasn't Dragon or we have so many reptile/Dragon-like pokémon since RBY but Dragonite was the only Dragon back then: they wanted, and want it that way. While many pokémon can be like Dragons, they aren't true Dragons except for a few. What I'm saying is that Fennekin becoming a Fire/Dragon, even though its initial design doesn't hint in any way to that, would be a massive curveball that I would totally expect from Game Freak. No one expected Blaziken's design, or Oshawott's samurai theme, or Emboar being bipedal out of nowhere.
Originally Posted by Fat R_N
"It's a mess is what I'm saying" - Slogan of GameFreak