Because I hate corporations hiding things from me. I may wish to check if a link is secure for one reason, or whether the address really starts www. (some do not). It's as unacceptable as hiding file extensions or any other naturally required information for that matter.
They must be still part of the address, or else confusion would reign. Some links are secure, some not, some addresses don't have www. so it seems it has to be that you are just not allowed to see it, because someone else decided you won't.