In fact, if these people really knew about bitcoin and the blockchain, they would find that bitcoin has been on an upward trend for a long time.
So it's obviously a good idea to hold bitcoin now.
They really don't know how crypto works, they are just only wanting to gain profits in fast way which is not really happen in here. Impatient people will surely loss and never survive in this form of investment. We knew market is not in the uptrend motion all the time and even in real stock investment, if they understand this trend, they might stop complaining.