I found a scholarly name for the tendency to rate goalies on winning teams as better than goalies on losing teams. It's the ecological inference fallacy. You can read all about it on Wikipedia, but in short it is the assumption that all members of a certain group share the same characteristics of the entire group. To quote Wikipedia:
If a particular sports team is described as performing poorly, it would be fallacious to conclude that each player on that team performs poorly. Because the performance of the team depends on each player, one excellent player and two terrible players may average out to three poor players. This does not diminish the excellence of the one player.
Nor does it boost the performance of an average player who happened to have great teammates. Avoid the ecological inference fallacy and give credit where it is due, based on an individual's contribution to the team effort regardless of the final result.
To see this type of thinking in action, go read one of the post-game report cards that fans put up after their team plays. In many cases, when a team wins there are As and Bs across the board. Yet when the team loses, everyone gets Cs and Ds.
Check out, for example, Vancouver blog Nucks Misconduct's report cards from last year's Cup Finals. In Vancouver wins, the average score for Vancouver fourth-liners was 9.1. When the Canucks lost, the average score for fourth-liners was 7.0. Can the Canucks' losses be blamed on a line that barely played and had little impact overall on the series? Of course not. It just so happens that when Roberto Luongo was making saves and the other forward lines were scoring then Victor Oreskovich, Tanner Glass, Jeff Tambellini et al looked better by association. In contrast when Luongo got shelled and the Sedins were shut down, the same guys playing their usual 6 or 7 crash-and-bang minutes without a goal for or against ended up getting hung with the same mediocre grade as the stars who were actually driving the bus. That's the ecological fallacy in action.
I'd say this logical error explains quite a few of the most common mistakes made in rating goalies. Add in the base rate fallacy that causes people to exaggerate their praise or criticism for a goalie's performance by not properly factoring in the play of a typical replacement ("Without Lundqvist, the Rangers would have lost at least 10-1!"), plus the fundamental attribution error which makes people lean towards personality-based explanations for team successes or failures ("Carey Price's teams will never win in the playoffs because he lacks mental toughness"), and finally availability bias ("I don't remember any of Mike Liut's career except for that Canada Cup Final where he let in 8 goals, but that game proves he was an awful clutch performer"), and you've probably covered 95% of the rest of them as well.