Yes, there is such a problem, but many exchanges do this, not just Kucoin. For example, on the Yobit exchange there is a lot of information and how its owners listing shitcoins and are engaged in their pump and dump, earning on their users. Perhaps we should choose exchanges that accept payment for listing in ETH, BTC and then there is a possibility that there will be no such problems with manipulating the price and dropping all the coins of the exchange received for listing?
Yobit sucks, and kucoin is well too. not comparable as far as volume or popularity. I prefer binance and bittex. High security, low trade fee, variety of coins.