Bitcoin does not promised you any profit.  that is one thing for sure.  So I kinda disagree with what you are trying to relay with your message.  The thing that bitcoin have use cases such as payment method, it surely gives itself valuation.  Besides Bitcoin is not controlled by any entity though it can be manipulated in the market which is not new since all stocks can be manipulated, even supplies of consumable goods. 

The fact that Bitcoin had established its audience and the way to mass adoption is getting clear, I can say, it is actually fine to buy Bitcoin.