Angry Birds sold 10 million copies on iOS alone in under a year. I highly doubt the majority of them would rather play a platformer that has been done to death over the last 25 years.
Sure and how many will they sell next year? Mario games, as a whole, have sold more than 210 million units: http://en.wikipedia.org/wiki/Mario
One single ringtone, Crazy Frog, made its creators a cool half billion back in 2006: http://communities-dominate.blogs.com/brands/2010/09/welcome... Sometimes you're just in the right place at the right time. Also, price/availability makes a huge difference--how many platforms was Angry Birds sold on and how much did it cost compared to Mario?
Lady Gaga may outsell the Beatles this year, but in 2015 it's almost near certain the Beatles/Elvis/Frank Sinatra and other classics will still be selling. There is always going to be a demand for new product, but the iconic games/bands/movies are still as relevant as before and there will be demand to have these classics ported to the new medium.
Mario games as a whole on the platforms they are intended for may have sold lots but how many people have bought the SNES, Gameboy etc versions?
We're talking about an old game on a device it wasn't meant for, there's no way your average consumer would rather that over a game built for the touch interaction on a device.
I think this is one instance where talking about the "average consumer" is meaningless, since if you define the average to be something like the median 50% of the population, you're still excluding the 50% of the population at the ends of the distribution.
