I feel that. At least with Dark Souls, you could look at the descriptions of actual in-game items discovered through thorough exploration and pick up on pieces of the backstory from that, whereas with Destiny you need to read the cards on the app/website or whatever to get the big picture. Still, you're right, plenty of the lore in Destiny wasn't even revealed until the DLC came out.

Once you actually get into reading the grimoire cards, Destiny actually has a pretty interesting backstory. It's just a shame it's not more directly implemented into the gameplay! I highly encourage fellow Destiny enthusiasts to read the grimoire cards because it really adds a lot of depth to the game. In particular, I find the lore behind the Vault of Glass to be particularly interesting.