I think it's a twofold problem:

1. The writing is extremely repetitive and the dialogue desperately needs an editor. As far as I know, nearly everything written by this particular writer has been poorly received. It is what it is. Find them another role within the team. The scene direction is very inefficient too. There are often 5 second pauses between line deliveries. 10 second pauses to watch a character clench their fist. Etc. That all adds up over 100+ quests, and it kills any sense of momentum in a scene.

2. Gaming attitudes change over time. There's a reason Everquest isn't the most popular MMO anymore. What people like changes over time, and it can be sudden. We may have reached the tipping point on "Talk to X, then talk to 3 NPCs". Sometimes gamers just decide they aren't doing it anymore. Again, look at what WoW did to EQ.