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”.