People spend time in bitcoin because it is an opportunity to earn in a fastest and easy way. It was proven by many people that there is a profit in bitcoin and others become rich through it. And i believe people doesn't think bitcoin as a waste of time rather a great opportunity to earn.
Spend time in bitcoin is worthy for me because it can really help and give opportunity to every one who seek extra income, just be patient and know what the bitcoin can possibly gives you a good future that is why you need to spend time with this.