The thing to keep in mind is that Poker Night wasn't really about the poker. It's about imagining what interactions the characters from four very different (but all hilarious) works would have with each other if they ever met. The game's basically a pilot to see if people would be interested in more "At the Inventory" games. Telltale went with poker for the actual gameplay because it's easy to program, easy to understand, and allows for lots of dialogue.
As an actual poker game, yeah, Poker Night's pretty bad, I won't lie. Once you've heard all the dialogue and gotten all the TF2 items, there's not much of a reason to play it. It's important to just remember that poker wasn't really the priority.