Because its good to invest in bitcoin coz bitcoin value is high so people wants to invest in bitcoin and the world is talking about its value.
They go grazy of bitcoin because of what they heard or read on how there life change for a better . Everytime they talk about cryptocurrency ,the first thing they put in mind is Bitcoin. It has higher percentage of people who is been dreaming to have a better life and they see a way on how to do it by investing in bitcoin and they go crazy to learn it more about it.
At the same time the value of the bitcoin continuously improves, where you can conclude that people wants to have an investment where as you can earn more profit than the usual, that is why maybe bitcoin really caught the attention of people. The people goes crazy simple because bitcoin is going to help the futures growth.