Wins and losses are a team stat, not a goalie stat.
Save percentage is a goalie stat, and a ridiculously good save percentage will usually let your team win. When it comes to game 7's, where both teams are relatively equal, he gives them the extra push.
When it comes to playing a team that is better like the Kings 2014 or the Bruins the years before, the entire team was outplayed and Hanks great save percentages did nothing for them when the team can't score.
To put it simpler: a goalies job is to give his team a chance to win, and there's undoubtably no goalie that gave their chance to win in the playoffs in the past ten years as Lundqvist has. His amount of playoff where he gave up 2 goals or less is astounding.