Here is my theory. Binance listed Yoyow long before Steem. Yoyow is a Chinese version of Steemit. Binance exchange originated in China. While Binance listed all the other top currencies, Steemit was one of the very last coins to be listed and yet Yoyow was listed from very early on. My thought is that Binance favors Yoyow to succeed and not Steemit.