I think the main problem of this project are those airdrops. Many people get that coin for free so they can sell it instantly and get some profit. They don't have a good reason to HODL. So the price won't go up so much.
Well the AirDrop is one reason to HODL. Since the amount of $ONIONs you get are in relation to the amount of coins you hold in your wallet: around 4%. So if you sell them off you will get less the next AirDrop. That gives a big reason to HODL. Since it is also a PoS coin you get annual 10% interest on your coins when staking.
But the main reason to HODL is because it is a good project imo.