To understand what console RPGs ARE, you have to understand what they WERE. The first video game RPGs were based (loosely) on D&D. They didn't have anywhere near as much customizability because the hardware and software couldn't meet the demands of such a complex system. However, even though the system was simplified, the games were still INCREDIBLY hard to play because they were mostly text based.

This is where Enix (yes, ENIX, you ingrates!) stepped into the picture. After playing a game called Wizardry, the general opinion around the office was that it was a fun game, but way too hard to get into. They determined to create an RPG with a graphic interface. The results: Dragon Quest (Dragon Warrior in the US). The results were a mixed bag between Zelda style streamlined gameplay and command driven Wizardry type gameplay. This was revolutionary for its time.

Enter Squaresoft. In a last ditch effort to make a game to save their company, Square released Final Fantasy, which was Dragon Quest only streamlined even further. The awkward command menu was truncated to the A button, and it allowed for multiple party members. However, because of the streamlining, and hardware/space limitations, the formula had strayed pretty far from its path. You remained totally in control of your characters and their actions, but the amount of options for controlling them was CRIPPLED by the fact that at that time, they didn't have the resources to really do that.

The game was a big success, so Square naturally decided to follow up with a sequel. This time around, they tried giving the characters some dialogue to make it act like an RPG. So even though you couldn't control what was being said, SOMETHING was being said by your characters.

This caught on big time, and DQ and FF were pretty much the canonical console RPGs at this point. As developers continued making games, the software and hardware became more advanced, to the point where more cinematic visuals could be used. This of course led to a more cinematic game in general. I'd say the high water mark was Final Fantasy VI, but I could be wrong.

So because the developers chose to advance the graphics more instead of working on making the games more interactive, what we have is essentially the same game as FFI, only with FMVs and summons. FFXI and other MMORPGs are closer to real RPGs, except that nobody roleplays.

Hope that helps