There are two reasons as to why the grimoire cards were one of the best things Destiny has ever had:
#1 They made it possible for hardcore players that were interested in the story to go deeper into it. While we certainly needed more in game story, the grimoire cards allowed us to understand this universe better than we ever would simply with in game details. The cards were easy to access, and they allowed for a lot of room for interpretation in this universe.
#2 The lore content creators. The grimoire cards have spawned dozens of Destiny lore Youtubers that present some really interesting interpretations of the cards, and they use particular means to do this. These creators, including Sir Wallen, Myelin Games and My Name is Byf, will now struggle with the removal of the cards.
As much as the lore needed to be in the game, the grimoire cards were also important for the people who wanted to read deeper into everything. Going in game to do all this is going to be such a hassle now. Seriously, how much would it have taken for somebody to write all the lore down? Bungie has taken a step back by taking their biggest criticism, a lack of story, fixing that, and then creating a new problem. I desperately hope that this changes in the future.
Oh, don't get me wrong, I do love being able to dig into Destiny's lore to learn more about the universe where it takes place.
I just don't like the method Bungie chose to deliver that information to the players.
When I was big into Halo I loved picking up a book here and there to read more on the Halo universe. It just made that universe seem so much bigger and fuller. Entire stories were just at your fingertips if you had any interest in them.
The way that the Grimoire was set up made it much more difficult to get a full story, at least while I was interested in a particular topic that is. You would have to search out ghosts, fragments or clusters and hope that they pertain to the story you were interested in reading. Otherwise it was back on the hunt for more ghosts, fragments or clusters.
When Destiny first launched I was very interested in reading about the back story, and I did search for for ghosts to help build up the world I was playing in. But the whole process of collecting only pieces of the stories just became more of a hassle than I wanted to deal with. I'd find a new ghost and think, oh, I'll read this once I get done playing ... but never would. So I just gave up looking for any of it. Unless it was tied to a quest. But even then I never revisited the cards again. It just felt too disconnected from the game.
So, yes ... I'm for getting information on Destiny's lore. But it has to be done better than Destiny 1's grimoire cards. Preferably in game.