Bitcoin is not a stock. So, I guess it doesn't matter what he thinks.
His opinion doesn't count if he think that bitcoin work that way.
Bitcoin can be profitable depending on how you manage it, depending on how you will make it profitable and effective for you. It is not about faith, this investment includes risks but there are factors which you can use to avoid losing at this investment and you have full control of you asset.
If his opinion is that bitcoin is not certain then he probably doesn't know the meaning of volatility in the market.