I don't think I am. Consider the case where one lacks the time or technical facility to execute, and only needs someone purely to 'implement.' Designers invariably are given a lot latitude, but sometimes the brief is 'Give me something like this.' One is unlikely to be required to completely rip off another designers work, those types of clients don't like spending the type of money required to engage a real designer, more likely they will engage a peon with no design aptitude and a cracked copy of Adobe Creative Suite, because their fee will be more in line with their expectations.

So when a client requires something, one delivers it. If in one's professional opinion one believes something else would serve the client's goals better, one runs it by the client. Usually they will be ecstatic with the designer's insight, as we both agree that designers are the enlightened experts here. However, sometimes the client will not like the idea, so one just knuckles down and gets on with it.

So it seems that it is you who is actually confused on this point. However when you graduate from Lancaster University, pass over from the world of academic pontification, and into the world of commercial reality, I am sure you will experience lucidity.