First, I imagine that there are a lot of technical issues related with the blockchain.
Second, if you produce 100 Steem daily, and you have 100 post published daily, then in average you pay one Steem each post. The next day you have 200 post and 100 steem, and the day after you have 300 post and 100 steem. And so on... If you don't limit the time to rewards authors, you will have a decreasing rewards each new day. Also take into account the new users coming....