Those guys tend to be big and tall. Tall = a lot of space your body takes up is above the net. You'd want a very fat, short guy, right? Well even if he manages

Those guys tend to be big and tall. Tall = a lot of space your body takes up is above the net. You'd want a very fat, short guy, right? Well even if he manages to be as wide as 80% of that net that leaves a massive 20% of unattended space. So now this extremely obese, extremely squat goalie needs to move faster than a puck to protect that 20%? Not gonna happen. And that's just hoping he can survive until the 1st intermission before you have to drag him off the ice as he's, you know, extremely obese.