Naughty Dog has become absolutely terrible in handling their DLC ever since Uncharted 3. Uncharted 3's multiplayer was plagued by microtransactions and essentially became a "free to play" retail game (before it's multiplayer component went straight free to play). The Last of Us also suffers from this.
I bought the season pass because I just wanted Left Behind and $5 for all the multiplayer maps was a god deal. What if I didn't? Last week I clicked the in game store and it took like 5 minutes to load all of Naughty Dog's DLC (and I already had pretty much all of it). I couldn't even back out. When it finished loading, I saw that if I didn't buy the season pass, I would be paying like $100 to get what I got in the season pass. The season pass is $20 but they sold weapons for $9? That's not even talking about all of the hats. It's insane.
It is sad that even though The Last of Us sold like 7 million copies on PS3, most people don't notice Naughty Dog's shady DLC practices. I hope people realize when they do this again in Uncharted 4.