I know that all the gamers have not been around forever. May not play as many games. And are generally still curious and new to all the gaming world.
So in retrospect i dont blame them for all the silly theories like : People dont like D3 because its not MMO , People dont like D3 because its not carbon copy of D1-2 ... etc
So for their service. And to prevent further confusion , i decided to bring you educated answer...
Here it is:
Diablo 3 has removed all skill customisation traditional to series, and RPG
Diablo 3 has removed all stats. Thing that is ABC of RPG. In Diablo 3 case this is also severely limiting number of stats on item drops aswell, which in term also nerfs item collecting fun.
Xbox graphics - No high res textures on 2012 PC game
No server browser ( just auto connect to random game)
So what we have there.
D3 is now officially less complex than any MMO or ARPG out there. Even WOW is far more complex.
Every good game goal should be "easy to learn difficult to master" , if they hope to have any longevity.
While in D3 we have only "easy to learn, than autopilot"
There is simply not much left for user to do - no customisation. Just collecting (now severely simpler items)
Less experimentation, less variety, less thinking = game that gets boring fast
On top of that every character is the same.
Every barbarian = your barbarian. (skill wise)
They even look the same...
While Diablo 2 because of large variety is still actively played today.
I got bored with D3 even after few hours.
Because of above mentioned simplification.
Diablo 3 is now simplified and dumbed down to rank of some Iphone game, or kids game like "Free Realms"
That is your answer folks.