From what I have seen, TellTale was going for a comic book style look to the game. I have a friend who is a HUGE fan of the shows (mostly SVU) and she LOVES the art style used in the game.
Super awesometasic graphics do NOT always equal a great game. For example, people say Final Fantasy VII is the best game in the series (my personal favorite was FFVI), but the graphics look terrible in comparison to Final Fantasy XIII, yet people still love VII. Why? It isn't because of the fanboys, rabid though they may be, it is because it was an awesome overall experience that still stands up today. Same goes for my personal favorite. The graphics are only a small part of the experience and should only factor into a review or opinion of a game for about 10-15% of the factoring about how "good" a game is. Taking that into account, these games are great because they are alot of fun and engaging to play and will likely be a future classic to come.