That is an issue if most think as well, the miners will keep dumping at a lower price with little incentive for people to buy. Will definately be watching the market as it progresses as a study in this type of coin distro.
Miners will keep to dump their Grin coin at prices that still bring profits for their mining after subtracting electricity cost. Therefore, we have to wait till the price at which miners get very little profits from their mining if they sell their coins at such low price. After that price range, miners will stop dumping their coins, and Grin coin will rally definitely. Waiting patiently is key for now if you have big interests in Grin coin.