I consider this trend a self-fulfilling prophecy. It is exactly because of the lack of the need for open world interaction, that people are starting to treat others like NPCs---because they don't matter the very least bit.

Dungeon etiquette existed in the days when no automatic matching existed. Take away the need to interact socially and social interaction disappeared. Electricity takes the path of the least resistance. People also do. Same with open world content. The whole reason jerks exist is because you, me, and every other player mean absolutely nothing to them. Similarly, the whole reason open world "content" are looked down as meaningless time-filler, is because there isn't content in the open world. Take away the content and travel becomes chore.

People who complain about dangerous open world content often cite the reason that they don't have the time to spend half an hour fighting their way across a zone. That is because they got used to the idea that fighting your way across a zone isn't content. Within that group of people, there's further a group that wants some reward for absolutely every second they spend in the game.

MMORPGs used to be a journey where the journey is all that mattered. The loot were just icing on the cake. Now the loot is everything, and the journey is called "a meaningless waste of time".

True, just having difficult mobs without the accompanying content depth in the open world is bad. But it's a step in the right direction. One day we may see a return of MMO players to the genre who appreciate the journey and game companies will start fleshing out the open world again. When that happens, jerks will become the dying breed and open world content becomes enjoyable. When that happens.