Mainstream is called mainstream for a reason. Because it is generally accepted stuff. These names you have mentioned are actually big names. They are guys who have achieved quite a lot in their own fields. So, it is only expected that folks look up to them. And when you look up to someone even unconsciously, you listen to them most of the time. The point many people are not seeing though is that being a genius in one field doesn't qualify you to be an expert in the other. Cryptocurrency is an entirely different world of its own. Something that most of these folks are not used to.