This thread's really devolved into people trying to define good and bad, right and wrong.
Honestly I'd say its because stuff actually happens in HoTD.
We've had like 5 episodes of pure setup (hopefully not 6). 4 and 5 have felt better paced, but there's a lot of storylines that feel like they'ved moved nowhere, while progress in other stories seems to happen off screen.
Meanwhile HoTD has friendships be forged and destroyed, plots hatched and foiled. Characters introduced, developed, and killed off. Each episode feels like its own chapter with a point.
Whereas I feel like just about everything in RoP takes 2-3 or more episodes to happens. It also feels like characters often fail a bunch just to have the plot hand them a win with little effort on their part, making all the time leading up to it feel wasted.
Arondir captured? Spend entire episode trying and failing to escape. Next episode they just let him go anyway as they want him to send a message. How convenient.
Galadriel needing to convince Numenor for help? Fails for 2 episodes and is about to be sent away via boat until tree saves her. Then takes a third episode to actually leave. Hilariously she actually says she convinced the princess.
Elrond wants to be friend dwarves again. They're grumpy but just get over it. He does nothing to prove himself, it all depends on their offscreen friendship.