Here's what I counter with:
1) Who cares? Nobody is complaining that NHLers have to be taller than 4'5"? How does this affect you and I, the viewers of this product?
2) Why haven't we seen 7'4" goalies already, if such an advantage is obvious?
3) There's a natural variance of height in our species as it stands. The global population isn't going to all of a sudden start producing more tall men, unless there's some underlying condition. Hockey cannot be that condition. So again, the current distribution of tall goalies will remain the same. Id argue the increase in popularity of the sport is what resulted in taller goalies. Canadians are generally short people
EDIT: Basketball also has a distribution of height. The entire premise of having to block shots is what makes basketball so tall, as well as having to shoot over those shots. The game is a battle of height, with skill helping along the way. Hockey doesn't have that issue. The goaltender is a batter of reflex, speed, and athleticism, with height/reach helping. Its the exact opposite in principle. Hockey goalies are freaky fast, not freaky tall.