I don't know where you got that idea, but it's not true. The Leafs continue to have the highest cost of tickets and continue to sell out every game. In fact, they've sold OVER capacity this season:
http://espn.go.com/nhl/attendance
They are also the most valuable franchise in the NHL (and have been for nine straight years now), and are second in the NHL in revenue, so people have obviously not stopped buying things:
http://www.forbes.com/teams/toronto-maple-leafs/
If you read the blurb about the franchise on the page linked above, it also states that the Leafs have sold out home games for over a decade despite only one playoff appearance in the past nine seasons (which was a total meltdown against the Bruins in the first round).
It will NEVER get to the point that you're talking about in Toronto. The team has been flat out awful with the odd playoff appearance here and there for nearly fifty years and the fans have kept coming and buying things. I mean, they're the most valuable franchise in hockey and they haven't won a Cup in coming up on 48 years. If that's not enough to turn fans away then nothing is.
I'm sorry to have to say that what you said in your post is blatant misinformation. Now you've been informed.
