First, a foreword to clarify that this is not a haters post. I am a big fan of pen-and-paper RPGs, including fantasy RPGs like Rolemaster and Vampire: The masquerade. I also find the Diablo series great, up to the highest-quality standards and groundbreaking designs of Blizzard.
No wonder why most people ask me why I'm not playing Diablo III, given I both like RPGs and Blizzard's games.
This is my personal view, and of course you may or may not think the same. I don't intend to offend anyone or start an argument between fans and haters. Just to present my thoughts and be open to (fair) discussion on them :)
Hope the following helps you understand my personal view.
What is an RPG?
RPGs (Role-playing games) are games where you assume the role of a fictional character in a fictional world. From this point of view most games (Super Mario Bros., Street Fighter or Duke Nukem to name some) would be RPGs, so I'll narrow the definition a bit more.
As part of playing that role, you're facing problems and decissions that you must take just as the character would do. So, now the character also has a personality that defines what you should do in a certain situation and you must act accordingly.
Their only limit is usually the imagination of the players and the game master (GM), so no videogame, card game or board game can equal that degree of freedom in what the players can find and what can do. The players themselves evolve as players over time as they face different situations with a limited array of gear and skills, just like in real life.
Trading card games
You will understand why I'm talking about this in a moment.
The typical TCG involves spending resources (money) in order to get a better deck to beat your opponent. A bit of know-how and slyness is also involved to win the game, but the determining factor is, by far, the deck you own (and thus, how much money you invested in it). In a tournament, where the players' skill is mostly on par, your chances to win are close to none if you didn't invest a lot of money on your deck.
This is why I perceive
Diablo as a form of trading card game
In Diablo, you have to invest large amounts of a resource (time) to get a better inventory to beat your opponent.
Most of the decissions you must face when playing Diablo are "What gear should I use to defeat enemies XX and YY?" And of course, that involves a lot of playing to get an inventory adequate for that. Little strategy and barely no growth as a player, contrary to what RPGs actually are.
A lot of asian so-called RPGs also suffer from this (the early Final Fantasy games come to my mind), as most of what enemies require is a high character level, rather than how to use their skills.
Of course there are some other decissions like how you want to raise the character stats or which skills you want to "purchase" for them, but their influence in the game is very low unless you have a gear on par with them.
Most fans will argue that PvP involves a lot of expertise than the normal game, but just like TCGs, when your opponent's expertise is more or less like yours, you don't stand a chance unless your gear is better than theirs.
After the beta, I missed the chance to upgrade the stats manually, and buying the skills you were interested in. The ability to define the characters' skillset on the fly was appealing 'though, specially if reverting a bad decission would mean to spend dozens of hours again in a new character otherwise.
I also liked that achievements were added, as they present you with challenging situations that you may not discover in the game otherwise. However, I still see this game's main mechanic as the endless loop kill tougher enemy - get better items - repeat. Some features are yet to be seen, like the auction house and the PvP, but I'm not sure they will add enough strategy to change my view on this game.
Diablo III is a great game, entertaining as their predecessors were; a cool way to spend some time. However, I only really enjoy games that make me feel I'm a better player at them when the end of the day comes.