Investing in Bitcoin is not risk free especially to investors who do not invest appropriately with the right approach and strategy, and also not sticking to their investment plans (long-term).
I disagree with your statement partly because long term investing is not risk free. Investing in Bitcoin or other coins certainly involves risk. If you are a professional investor then you are used to taking risks as the price of any currency is not always the same and fluctuates constantly. This is the picture we see in the cryptocurrency market.
I think @Kliss is right and you are the one that is wrong on this. Perhaps you read the statement the wrong way and what it actually suggested was that if you do not invest appropriately and think long-term, then investment in bitcoin will be very risky for you. There is no lie in that statement because people who lose money to bitcoin are those who buy bitcoin and hoping to sell quickly and recover their investment and make profit. They probably invest bigger than their capacity and will not be able to hold longer should price refuse to pump, so they often sell at loss because the money put in bitcoin are money meant for other things and cannot be kept in bitcoin for long.
Investment in bitcoin becomes highly less risky with the right approach such as using the DCA method and setting up the necessary control measures such as emergency funds, reserve funds and any other thing that will sustain the investment. Like @JayJuanGee stated in an earlier comment, investment in bitcoin should be given between 4 to 10yrs as the minimum that is considered long term.