Running a witness for Steemit is a bit more complicated than running a masternode for say Dash. The steemit witness server requirements are more robust and require larger amounts of memory to function well. Steemit has always been top heavy because you could mine it in the beginning and create multiple accounts while doing so. The top witnesses get paid a ton, but those at the bottom may not even be able to cover costs. To give you an idea of how top heavy Steemit is check out this post from a while back https://steemit.com/blocktrades/@blocktrades/buy-steem-accounts-with-pre-loaded-steem-from-blocktrades If you look at the distribution of Steemit wealth you will discover its even more depressing than some fiat models.