Hm... It seems you keep changing your post. You basically classify two classes PRs: one from programs that would hurt the economy if cancelled, the other from programs that are "cancellable".
And you think it's not OK for the former to have benefits without contributing, but it IS OK for the latter to do so, as you can stop them from coming in any time you want?
Let's say I agree with you on this, even though you have a bit unusually way of thinking about this. What does that have to do with Canadians abroad? Just because you cannot stop them from coming back, you have to ban them from using benefits?
But you cannot stop the Canadians inside Canada from not working to pay taxes, either... And you are OK with them having benefits? Why is LOCATION so important to you?