Yeah i agree if all of ua would just hold in steadily to our btc's pretty much there's not gonna be any movement thus the currency would have a hard time progressing.
Actually I can't picture out the sense of not selling it. Well if in the case, althought the odds are low, that all people will hold their coins, the bitcoin price will thoroughly increase since people will force to buy coins even at the higher price but of course they will not sell it.
So literally speaking, their actions are non sense. They hold to sell and not to hold it forever.
Once upon a time you of course have to sell your bitcoins but right now its better to just hold on the bitcoin and wait on a better time because there will be a better time for sure without any doubts.
We just need a bit of patient and than sell it for a good price.