I read this argument somewhere, which I thought somewhat convincing:Where do you draw the line? What if we end up with 50 teams in the league? The more teams there are the more fan bases there will be who will end up going a very long time in between their team being a legit contender. On top of that it waters down the talent and waters down the rivalries. We need less teams not more
The other "Big Four" sports leagues are in 29-32 major American markets. The NHL thinks they can and should have 28-30 viable American markets too.
Hockey just has a unique cultural place in Canada, which is why it's the only Big Four league with non-Toronto Canadian teams.