Looking at it from another perspective, I think the problem is that a lot of games which aren't RPGs are being forcibly squeezed into the RPG genre by fans who perhaps want them to be labeled RPGs.

RPGs have:

1. An experience system to "level up" and improve your characters
2. A statistical system to make the abilities of the in-game character independent of the player's gameplay abilities.
3. Different items and the ability to equip and use a variety of things.
"Real World" activities, such as the ability to shop, go sleep at an inn, rest up between adventures.
4. Interaction with the other characters in the environment.* This is optional interaction, usually performed by walking up to the character in game and pressing a button to get a box of text. It is not mandatory cut-scene sort of interaction which always happens at a fixed point in the game. (* = Interestingly, this was a development not present in the earliest RPGs such as Wizardry.)
5. Have some sort of storyline which has meaning to the game in some way other than merely framing the action.
6. RPGs are turn based, or if they involve action, they are a real-time emulation of a turn based system. This is because RPGs are thought based instead of twitch based. RPGs test decision making abilities, not reflexes.

So, under those criteria:

RPGs:

Lost Odyssey
Shining Force
Puzzle Quest
Ultima IV: Quest of the Avatar
Enchanted Arms
Final Fantasy VI
Bard's Tale 1
Eternal Sonata
Ogre Battle (while realtime, reflexes are not the primary factor being tested, decision making is the priority)
Growlanser Generations

Not RPGs

Warriors Orochi (no character interaction, no "real world" activities, not turn based)
Zelda games (not turn based, action more decisive than statistical system)
Castlevania games (not turn based, action more decisive than statistical system)
Super Paper Mario (not turn based, action more decisive than statistical system)
Culdcept Saga
Advance Wars
Untold Legends: Dark Kingdom
Elder Scrolls III: Oblivion
Marvel Ultimate Alliance