When looking at Nintendo games, I would agree that "more and more games are made based off of that same business-principle." However, after the bright refreshing light of valve shined on me, I realized that some games could still be original. Based on intimate personal relations and satisfying story lines, games like Half Life (2 etc.) and Portal show a whole new idea put into gaming. Of course some people may disagree with me, but it was because I had never heard of any valve game before I played it, and my low (or lack of) expectations contributed the the enjoyment that I got out of them.
Of course, I still play Mario and Zelda games because they were the originals, and they have the right to keep the same game idea for that reason.