Why can private helper methods still be accessed in views?
Helpers are modules that get mixed in to the views. This means that public, protected and private methods in the helper become public, protected and private methods on the views.
I don't think that you can actually hide the helper methods from the view. You'd need to do something like have a helper class which you instantiate in the helper and then delegate calls to that - sounds like it could get messy fast though. :)