The supply that is left is going to take around 7 to 10 years to be mined still, and like any other coin that will reach to their cap the rewards for the miners will be the fees from the transactions. Plus if you understand how supply/demand works the more coins are in the market supplied by miners the more buyers you need to have in order to keep the price up now when you have new buyers but no more coins getting in the price will inflate and not  "down like Titanic" because now people are fighting for a limited number of available coins. Following your logic Ripple would be down the sink already as they have 3 times more coins in circulation than we do.