It's definitely odd, and the main reason is that new coins have highly active devs who seek out exchanges to get listed on. STEEM doesn't really have a centralized team per se to take steps like that maybe? I'm not sure..
I hope we get listed anyway because Poloniex sucks and I feel it's bordering on the edge of being a fishy exchange, and Bittrex is losing more and more ground to other exchanges. It would be great to just ditch it altogether and do all my trading on Binance instead. Plus, Binance is an Asian exchange, which means more exposure of STEEM in Asia (and they love crypto!)

Thanks for the support!