Re-Branding: true value or "pulling a fast one"?

I want to pose a question that was haunting me through the entire class on re-branding. We’ve covered re-branding in relation to mergers, acquisitions, etc., but no one spoke about re-branding in order to change a negative customer perception while changing nothing in the way the company does business. In my experience, about 80% of re-branding happens simply because the company wants to be called something else, to have a new logo, and hopefully, granted temporarily, convince its customer that they are better. Unfortunately, what I don’t see is the change in the actual quality of the product or service; at least to the average consumer (there are always exceptions for the large accounts and squeaky wheels). This, in my mind, makes re-branding “an empty gesture”, an attempt to create perceived value without any sustainable way of maintaining it. So are the majority of re-branding efforts really are “pulling a fast one over your customer” [I want an opinion from your experience] or am I missing something?

Alex