Could a morbidly obese goalie shut out an NHL team?
online.wsj.com
online.wsj.com
Traditionally it was "the fat kid" who played goal, since anybody who could skate would rather put the puck in the net than get whaled in the nords.
I believe this changed when modern netminders brought more skill, athleticism, and even dignity (really) to the position. Plus, people love all the cool-looking gear.
And, indeed, unwritten rules are handy because they can be changed on the fly as necessary.
You just couldn't get a goalie who was big enough to fill the entire net, so the increased goalie size would limit his mobility and make him worse.
It is nice having a 6'8" defenseman who has a longer stick than normally allowed though.