As it stands, DarkCoin can live forever, if the artificial 84million cap were removed. It is still rare, it takes a century to get to 100 million. Look at the United States Deficit! It's in the Trillions! And people think 100 million coins for the world population is too much?
Bitcoin won't die just because it'll stop producing coins at some point - otherwise no-one would buy it thinking it's dead and buried already. There's still transaction fees to be mined after the coin generation phase and if the coin has endured for so long, that means it will have transactions.
Finite and scarce coins are always better than infinite crapcoins. The elite-hoarding argument is true for every single coin in circulation. If the elite have the money and want to buy in, they can buy anything they like and hoard it.
It is not infinite if the demand outpaces the supply, by a lot! And bitcoin is already stagnant. It sits like gold in a vault, under your bed, behind the couch.