Not sure if it's trivial, but I really hate broken bridges. I'd like to be able to go wherever I want to go, whenever I want to go. If I want to get the 8th gym badge first, I should have the option to do so!
About the Dream World tutorial thing, isn't that due to not saving cookies? I've only ever seen the tutorial twice. There is that movie every time to you enter, but that has a button for skipping it.