If I were in the Poloniex team, I'd make a new and powerful image change. Then I would try to create a hype with a big advertising campaign.
It's so difficult to bring back the credibility of old poloniex again, the developer of polo has destroyed its own exchange site. Not only polo but as far as I remember bittrex was doing the same thing to its exchange site.
They were blatantly blocking a lot of accounts without any reason.