Waves is doing great things. Once full nodes is released, I don't see why Poloniex wouldn't add it.
Its easy to manipulate buyers and sellers when its only in one exchange. They can easily get money and need not to put buy support for all exchanges that adds it.
-Doesn't the reduce the market for them? I mean,it's shared on country basis,people from specific countries are inclined towards polo and some bitrex.In my opinion,limiting the currency to one exchange redues the market,not a coin devs team would want that.The more coins sold would result in higher profits,right ? Even easier to pump them up.
-They don't need to put money for support but to promote their coins in exchanges.
-Waves is a different scenario.Don't compare them with other shit coins.