Even if we are willing to lose and do not expect to receive any reward when investing, it also means that we have accepted the risk as freely as possible. Investing in bitcoin meant we took the risk, but given what bitcoin can give us, I think our risk is well worth it.
There is no such thing as a completely safe investment in this world, it's just more or less risky, and bitcoin is one of the riskiest investments compared to traditional investments. But high risk brings high returns, so if someone is willing to step out of their comfort zone and take the risk, they will succeed faster than others.
I think that's one of the big advantages of Bitcoin, that you can, since the beginning, simply risk a portion of your time/money/resources to it, and see how it will go.
Probably it's not as high risk now as it was in the beginning, but for some people it is still seen as high risk.