This is a pretty old article (September 2014).
Although the number of bitcoins is finite, it doesn't automatically mean that bitcoin's price will shoot up if adoption increases. You could have bitcoins circulating at a faster rate.
wider adoption means more people spending their coins, but also more people holding their coins in the hope the price increases. and by the time wallstreet pops up and start with buying up plenty of coins the price will shoot up like a rocket.
Correct the reasoning of pattu1 according to me. But even it wasn't true this, even the circulation, I think, cannot stop the increase of price. The number of people in the world it will be much higher and every day will be new people in the world of bitcoin and new people which born. Those factors will be more important in question of the price of bitcoin than the fast circulation. In this way they will eliminate day by day the fast circulation and will increase the price of bitcoin.