Because people don't care about those things. People are information processors (this is a central premise of Swarm Theory) so they go to where the information is. This is why network effect is a thing. The more people in a network, the more information is generated, the more valuable the network becomes to more people, who then join the network, and so on. This is why so much work with Steemit went into onboarding. Steemit, Inc. was literally losing money every time they onboarded a new user! There were so many challenges with creating a social network on a blockchain and Steemit was a classic example of the dangers of being "first"; you have to solve all the problems.