As long as there are markets which we can all have access to, then price discovery will be possible. Markets, especially emerging ones, are incredibly emotional.
At the moment we need exchanges because of the price volatility, so if we ever trade bitcoin, we are, straight away, checking what the latest price on an exchange is.
However, if that spot price on the exchange stayed the same for a while, people eventually won't bother going to the exchange to see how much their bitcoins are worth.