Mike,
To answer your question, IMO the answer is no, and in fact the design should reflect this to maintain strategic interest. With the proper shot, it should be possible to get close to the majority of holes in a round, and that could include aerial or ground approaches. I also see nothing wrong with a couple of holes per round with no reasonable way to approach them that overcomes the risk.
That said, I believe that for the overwhelming majority of golfers, the answer to this question is an emphatic YES. I wonder if that factors into design, and if so, in what manner it forces design compromises. I would assume designs decisions are made with the preferences of the target market in mind, but also wonder how this affects public courses that go private and vice versa.