That is an rhetorical question which probably might be no answer. But that not withstanding,  as you know bitcoin is a decentralized currency that need not physical assets to control it. You control yours and I control mine. You should not wonder because investment is not by force. I thought you would asked for the legitimacy of the currency. Investment is a personal interest if you want to do it you are free and if you don't to do it is all your choice.

And another thing you have to consider is the platform, so if you want to invest on bitcoin, asked questions to know the genuine Trading sites to invest. You don't have to be afraid as you are here. What you have to do is to read other threads and learn from them. Your inquisitiveness will determine your out come. So be focus and learn.