If the price increases too fast, the cattle will sell it fast, and this will break the exchanges which will not have the money to pay for it (except for the one who sold those bitcoins to the billionarie).
The ideal is to increase a hundred dollars per month, with daily fluctuations around two hundred dollars, so that they can hold a little longer.
I think it is lacking a bit of education on how to use bitcoins, on how to make it acceptable. Most merchants wont accept it and that is one of the reasons the noobs will not hold it.
Exchanges don't have to pay money to bitcoin sellers.
Exchanges just have to find buyers and sellers. No matter which way the price moves, they just match trades and make profits.