The price of cryptocurrencies basically follows the rules of demand and supply. As the coin becomes scares it becomes more valuable and hence the price increases. One common mistake most investors do is that, once they see the price of a coin is going down, they hastily dump what they also holding which increases the supply more than the demand and further reduces the value of that particular coin. Later we try to put the blame on the team that they are not managing the project well. Let's help sustain our coins by avoiding panic selling. Its a collaborative effort.
I totally agree on you OP! But can't blame also the investors who dump their coin to the market because they are just cutting their losses. Most of the people doing this are those who engage in short term trading. They want to cut the loss and transfer their funds to more profitable coin. In this way, they could not loss their capital in that coin only. Doing this thing, help investor to strengthen further their holdings in the market.