Yeah. It's where they've lost me with this game I think.
Technically, if it was all released in one piece together, you can get away with 5 missions that don't show the storyline, but slowly introduce things. Because you'll swiftly pick up the story that pulls you in. But after 9 months and no real storyline that's catching you as a character, its very awkward to stir up the enthusiasm to go to the next episode. Sure, the gameplay is technically excellent and a lot of fun, but after 3 or 4 episodes of that its only part of what pulls you with a Hitman game.