Telltale should be trying to do more than just standard adventure games
Why? They are special for it. A lot of people love them for it. They have sold 5 millons of chapters because they are "standard adventures". If they do action adventure games they suddenly are a one-more company of hundreds.
This step from Telltale is not new, look at Tim Schaffer with his Brutal Legend, it is a good action adventure game with a story and for what I know, It hasn't sold too well, it was 50% off on my country a month after the release... It is very difficult to compete in the action adventure market.