There are worse players than Ray for sure. However, the expectations are lower for those players. Nobody expects anything out of the 4th line, but a first line winger has to put up some points, same with second line and PP2.
Pretty much everyone made mistakes in that game, and the Wings almost managed to outscore their mistakes. Aside from DBoss, DCat, Joey and Ghost, anyone could be a spacegoat. Those 4 outscored their mistakes.
Edit: To make a better case.... remember when Mantha was spacegoated a lot? Not because he was the worst player on the team, but because the fans expected a lot more.