Why would everyone invest only in crypto market? well its their choice maybe because they saw more advantage on it rather than just one particular project, perhaps they saw more potential profit are being laid there.. and more advertisement is shown.
They are investing in crypto because they are tempted by the high price of bitcoin in December 2017 which is close to US $ 20,000. Who would have thought that the price of bitcoin would be that high? Everyone wants to invest and enjoy the benefits. They do not realize that crypto is a currency that has fluctuations so that investment can be profitable but it can also be a loss.