From the past experience and observation what I have learned is, people mine or stake such coins by studying its actual potential, still they will dump their rewards at current market and makes finally those coins get delisted from the exchanges. I mean they will choose highly potential (or best in your terms) but they will never prefer to hold the rewards; that is the actual problem here with such POS/POW coins whereas tokenecomic are not facing such problem.
At the same time, people who mine are not noobs to dump their mining rewards. I mean they will keep on holding when they realize there will be the future of those coins. At the same time, miners will choose coins based on current market value so that they could cover running costs of mining process. Hence, dumping the rewards in inevitable for them but they will opt to hold some 10% to 20% of rewards but based on potential of a coin.