Dual types and the people who don't exploit.

[CAMountainSnake]

Why is it that people suggest movesets for Dual type pokemon that get STAB attacks from only one type. For example, Charizard and Aggron. No one ever gives a decent move set that utilizes the Flying type of Charizard or the Steel type of Aggron.

[Poryhedron]

In Aggron's case, Steel-type attacks simply aren't that good. Metal Claw is under-powered, Iron Tail is inaccurate, and Aggron doesn't get Steel Wing.

[rinku]

I'm not sure what other people do, but I always consider that angle. Some cases are over-obvious (Dragon Claw on a physical attacker Salamence or Earthquake on a special attacker Swampert) but you do need to weigh up what final power, as per Poryhedron's comments re Aggron's Steel moves.

For example, Steel is only Supereffective vs Ice and Rock, and is not supereffective vs Ice/Water, Electric/Steel, Water/Rock and Rock/Steel so a power 50 (STAB 75) Metal Claw is generally inferior to a power 75 Brick Break (which is supereffective vs all of the previous types, plus Normal, Dark and Steel). Iron Tail is more potent, but 75% accuracy makes it less attractive and it is still less effective vs Ice/Water, Electric/Steel, Water/Rock and Rock/Steel than Brick Break.

Also note that Aggron's Rock type is itself supereffective vs Ice, though Rock Tomb and HP Rock are its only RS options there (Rock Slide through the FRLG move tutor I believe). Rock Tomb is just as effective as Metal Claw vs Aerodactyl and Arcticuno.