Recently I put some order at localbitcoins.com to purchase and sell bitcoins, to my surprise, there are many people buying bitcoins from me, but I have not received any sell orders, so I have to actively buy coins from other exchanges
So it seems that most of the people do not want to sell their coins, or they just don't have enough coins to sell. The statement that most of the coins mined will be sold immediately at market price is not true. The current sell presure mostly comes from early investors
This chart shows how 10%, 20% and 50% cash out strategy by investors will affect the bitcoin daily supply. If the mined coins were mostly hoarded (acquired through investing in mining devices), then the daily coin supply
on exchanges will mostly consists of coins cashed out from early investors, this will reduce the amount of supply on market and increase the exchange rate
Mining is a cheap way to acquire coins, since it does not affect the market price. Only when mining becomes unprofitable, people will start to purchase coins on exchanges. So before the difficulty rise another 10 fold, we might not see a lot of buying support on exchanges, that is another 6 months