Poloniex still need to do very big work in winning the interest if users and assuring them that they will not pack their bag again the second time to leave the market, and while trying to do this, Binance will keep coming up with strategies that will make them o continue staying a leader to them all.
What people care about is service, promotions, and kinds of other benefits they can get from exchanges they use. I don't deny that fact that past reputation and current total volume on exchanges are determinant factors that significant affect choices of investors or traders when they have to choose between exchanges. For whales, or experienced investors and traders, they care more about security and reputation of exchanges. In contrast, small traders or investors tend to prefer exchanges that can give them short term benefits through give aways, promotions, ref rewards and so on. Poloniex is a US. based exchange, so it has to obey strict rules in that nation. However generally I don't think Poloniex actually has bad reputation.