I’m guessing it has to do with making the NHL look like a Mickey Mouse league when you pick up guys off the street and have them playing in NHL games. I don’t know what the alternative would be tho because you’re screwed without a goalie and it’s such a specialized position.
There is a difference between having 2 healthy goalies get injured in a game vs going into the game with only 1 healthy goalie.
For some teams, there is no excuse when at home and the A club is within 2 hours of the NHL team. If someone got hurt in the morning skate, you have to get someone up for the A club. But, not every NHL is close to their farm team. Edm, STL, TB, Sea are not for example. And when on the road, really not much chance that you will be close to the A club.
MLB - run out of pitchers, have position players go in and just throw 80 something mph fastballs.
NBA - run out of any position, either go big or small. Hard for big men to dribble the ball out but that's life
NFL - no QB, like we saw SF in the Champ game vs PHI, pretty much just running the football
MLS/Soccer - not that hard to replace the G with someone, as there are way fewer shots on net in soccer than hockey.
NHL - no goalie, hard as there is the extra equipment which is custom for the goalie. And, I doubt skaters are as flexible as their goalies, so potential groin injuries to them if they are asked to go in net. Can't play 6 skaters for more than a couple of minutes to close out a game.