If someone had told you during 2015 that Bitcoin will exceed over $100k one day and you should invest in it as at then. Would you have believed?
Ha ha ha, 
no, I never believed that. People believe in cash. They do what they see. Also, around 2015, we heard about some currency scams. At that time, people knew Bitcoin as a scam. So most people tried to stay away from Bitcoin then. Later, with the evolution of time and the blessings of technology, people started knowing the real truth, then the importance of Bitcoin started increasing. So I think at that time, people did not want to invest spontaneously like today.