I'm going back and forth with myself, trying to figure out if I agree with you. On the one hand, I can see what you mean. Looking back on it now, Mario Bros 3 doesn't seem too innovative, but try and imagine what it was like when it first came out. Yeah, it was still about jumping on turtles and grabbing mushrooms, but there were so many new things! Power ups galore, an over-world map that provided multiple paths, and so many levels that you were almost guaranteed to leave your nes on for days if you wanted to play straight through it.
My mom worked in a video rental store when I was a kid, and so I spent hours upon hours playing any games that weren't rented in the back room. Mario Bros 3 was almost impossible to get a hold of though. It seemed like the minute it came in, it'd be right back out the door again. I mean, it was just an insanely popular game, and for good reason. It was everything that made the original Mario Bros so fun, only bigger and better.
My sister opened a computer store in Hawaii. She sells C shells down by the seashore.