2$ or 14$? it's about volatility and market speculation. It could drop to 50cents of a dollar tomorrow, who knows.
Pegging the coin to USD would give it more stability, i.e. you would be sure to convert your earning at a certain fiat rate.
My opinion: what's the point keeping a fiat reference (USD) when dealing with cryptocurrencies. You're loosing all the centralized/trustless added value.
It's about getting mainstream adoption. Average Joe won't give up his stable fiat currency for a volatile cryptocurrency. We need a stable cryptocurrency to bridge the gap and provide a gateway for the mainstream to move into crypto. Then once we have mainstream adoption then the market will be big enough that volatility won't be a problem. At that point we can ditch fiat altogether.