This isn't the first site to try something like this. Tsu was quite the upstart about 3, 4 years ago. Had some big names one there, too! And you could donate to charities like Charity Water, Make a Wish Foundation, and otherwise.
Tsu failed because too many users spammed the shit out of it, hoping to make a quick buck. That and they couldn't get good, sustainable advertising to support the network. Steemit has one of those issues, and (hopefully) people can fix it. Building up a community goes a very long way here.