This discussion may contain spoilers!
Oh, Walter...we hardly knew ye. Only one episode to your credit, and you've already bit the dust.
To be honest, I was a little taken aback by just how idealistic Walter seemed, especially during his chat with Clem outside the ski lodge. Two years into the zombie apocalypse, and this guy was holding himself together surprisingly well. Granted, Walter's cheery attitude appeared a little forced - which might explain why he was so primed to explode when he found out about Matthew. It was clear Walter was a sensitive and deeply intelligent man, but as with most intelligent men, his attitude was all theory, and no practice. When actually confronted with death, Walter came a hair's breadth from snapping completely.
All the same, Walter's murder seemed almost inevitable long before it even became apparent. Maybe that just goes to show how predictable Kirkman's universe has become in its own dark, sneering way; any guy who even remotely suggests there's a rainbow waiting behind the storm cloud gets hit by a bolt of lightning. I doubt this was Telltale's intent when they writing the game, but that seems to be the message regardless.