The issue is the pros and cons of being transparent.
Being transparent is good for the players, but bad for the developers. It means laying out all your cards on the table and give players expectations that might not be able to be fulfilled. More importantly, it implies(even if you don't do so explicitly) timescales... If I make a post implying that some specific new content is being made, players are going to wonder where that content is every month it isn't released. Without being totally transparent(and thus spoiling the content) players can't really get up-to-date news on what kind of hurdles development encounters. Look at what happened with the railroads... it took WAY longer to make than I originally anticipated, but for good reasons. It didn't really calm the players down at all no matter how much I tried to be reassuring that it wasn't "dead" or "forgotten."
However, not being transparent means development staff doesn't have to worry about disappointing players and working at a pace optimal for quality content(which sometimes means slowing down and not rushing it). The downside is that players have no clue what's going on, and can often imply nothing is being done because there is nothing to show for it.
Also, be aware while there seems to be a lot of "pointless" content, that pointless content has a purpose. What I mean is when you release content in a game like Graal, which is heavily Zelda-influenced... releasing all the new content at one time pretty much spoils the exploration aspect. If I were to release a quest that involved say... a lost item you find in a cave and at the same time released a new NPC that just so happens to be looking for her lost item it completely ruins the aspect of piecing together clues and figuring out the quest. So this "dead" content serves an important purpose of being there to be used in the future without being obviously new. I rather not leave a bunch of pointless stuff that implies content for new players, but there is a sort of balance that needs to be achieved between not giving players false impressions and leaving a foundation for new content in the future.