Never. Too many expectations, and if it's a huge flop, then the company is really going to pay for its mistakes. It could be a huge failure, or it could be really good. Even if the game is great but the story is sub-par then the community is going to hate it. Not to mention that the original story writer (or one of them) left Valve a long time ago
"It never hurts to keep looking for sunshine" - A. A. Milne