Its about the money. Teams/cities bid to host the tourney. Then they make money (or lose money) off the event. There's flights and hotels to book, volunteers to secure etc, its not logistically doable to not have a predetermined host.
A few surprises in there for people that didn't know and how much things that happened long ago made sense in retrospect.
My own biggest pain was listening to the radio coverage of the games and hearing the 71, and 72 Oil Kings beat. I went to a lot of the games in those years, particularly playoff games. The 72 Crusher against Guy Lafleur the biggest heartbreak.
The biggest ever success was the Kings beating Bobby Orr in memorial cup play.
My thinking is that the team with the most points in all three CHL leagues would get to play in one of the elimination games for the Memorial Cup. All the winners of each league, OHL/WHL/QMJL and the team with the most points of all 3 leagues. If that team is already the winner of their leagues trophy, it'd go to the team with the 2nd most points in all the CHL. This year the team with the most points in all 3 leagues is the Kelowna Rockets with 118 points. They should get to play instead of the host team. So it'd be something like, Kelowna Rockets vs Geulph storm, Edmonton Oil Kings vs Val-D'Or Foreurs, and the winner of those 2 games will play for the Memorial Cup. I think that would be more fair. It'd also be a good incentive for a team to try and win and get as many points as they can in the regular season because that would guarantee them a spot in the Memorial Cup playoffs.
That would be the best way to go, in giving teams that most deserve to be there. However, I do understand that promotions and good ol' l'argent is important too. Most often, the host team is able to recruit alot of good players, because they can guarantee a player they will be in the Mem Cup. So, usually, they are pretty decent anyway.