From Diablo Wiki
"Accessibility" is a term Blizzard uses to describe one of their core game design values. It's part of their "easy to learn, difficult to master" theory, in that they want their games to be very easy to pick up quickly. The design goal is to get new players playing the game immediately, without high system requirements, or controls that are difficult to master, and the theory persists throughout their games, where game systems and features should never be needlessly complicated.
Fans do not disagree with this theory, but the actual details of making games "accessible" often create controversy as "hardcore" fans often argue that some features are being "dumbed down" in the process of making them more accessible. Numerous system changes in Diablo III fell into the gray area of the "accessible vs. dumbed down" debate, including major system changes like no skill points, auto-assigned attributes, no attribute item requirements, freespecs, initial game difficulty, and more.
Blizzard's Increasing Accessibility
One controversial element of accessibility comes up in debates over the changes in World of Warcraft's focus. Many long time WoW fans dislike the changes made in Cataclysm and exacerbated in Mists of Panderia, as the developers have made raiding much more "accessible" and therefore easier. As Seth Schisel described it in a New York Times article:
- In terms of the game’s design, the overall tone and difficulty have become much more accessible to casual players. The sorts of high-level demons and dragons that traditionally would have been conquerable only by people who played dozens of hours a week can now be felled by pickup groups of moderately skilled players.
This is presumably more welcoming and accessible to new or returning players, but many long time WoW players hate it, as they don't find the "more accessible" content challenging.
This is a game design theory that many in the Diablo community find unfortunate, and the fear is that nothing in Diablo III will be difficult or fast-paced enough to truly challenge a skillful player. The developers insist that's not the case, and that they can do both. That Normal and Nightmare difficulties are fairly easy, but that Hell is much harder, and that Inferno is balanced so that only truly expert players can succeed.
Furthermore, the robust support for Diablo 3's PvP via the Battle Arena should give expert players long term challenge, since other players will test player skill to the utmost.