Then you must make Diablo IV way much better than Diablo 3. Make it greater! Also, listen to previous Diablo fans. Stop ignore them, or we all lose faith in Blizzard.
You got two options:
1.) Make your game however you want it, it’s a 50% chance we all would hate it or love it. But it’s a scary risk to take.
Or
2.) Listen to their fans. = WinWin
We all just want an epic Diablo game, that everybody loves!
Not another Diablo 3 clone game.
Both your points, while valid, provides nothing other than a circular argument.
Why? 
Because no matter how Blizzard designs the Diablo IV, or to which feedback (negative or positive) they respond, there will always be some who hate the end result and some who love it, and all others in between.
1 -> 2 -> 1 -> 2.
Circular Argument.
You’re making it sound so easy, as if all Diablo fans want the same things from the game…
Some fans want trading, some don’t. Some want pvp, others don’t really care.
Long story short: there is no such thing as “this is what fans want”. It’s all very subjective and there are so many different opinions.
Blizzard is already listening to fans, but in almost every feature and topic, decisions need to be made. Decisions that will make some fans say “Yes! that sounds great!” and others “If you do that, I am not going to buy the game”.
Those who try to make everyone happy, ends up making noone happy