What purpose does the Game Winning Goal stat serve?

Of all the stats in sports, the one that makes the least sense is the Game Winning Goal in hockey. Let's look at the Kings 4-2 win in game 2. The scoring went:
1st Period LA - VAN
19:51 Los Angeles Kings LA
Dustin Brown 2 (shorthanded) (Assists: Anze Kopitar 2) KINGS 1, CANUCKS 0

2nd Period LA - VAN
0:17 Vancouver Canucks VAN
Jannik Hansen 1 (Assists: Henrik Sedin 2) KINGS 1, CANUCKS 1

5:17 Los Angeles Kings LA
Dustin Brown 3 (shorthanded) (Unassisted) KINGS 2, CANUCKS 1

3rd Period LA - VAN
8:30 Los Angeles Kings LA
Jarret Stoll 1 (power play) (Assists: Justin Williams 2, Dustin Brown 1) KINGS 3, CANUCKS 1

14:51 Los Angeles Kings LA
Trevor Lewis 1 (Assists: Dustin Penner 1) KINGS 4, CANUCKS 1

16:22 Vancouver Canucks VAN
Samuel Pahlsson 1 (Assists: Keith Ballard 1, Mason Raymond 1) KINGS 4, CANUCKS 2

Stoll's goal which put the Kings up 3-1 midway through the third period holds up as the GWG and is credited as such when the game is over. However, it didn't win the game. It merely made a 2-1 undecided game a 3-1 undecided game or in other words, it was only an insurance goal.

Since it was unknown at the time of Stoll's goal how many goals the Canucks would score, the GWG can't be used to measure clutch. Take for example a game in which the Kings beat the Canucks 6-1 with the Canucks closing out the scoring with their lone goal in the final minute of play. With that final goal, the Kings GWG changes from goal #1 to goal #2, yet there is nothing to indicate goal #2 was more important than goal #1 or any other Kings goal.

So just what are they trying to tell us with this Game Winning Goal stat?