I don't think that Kucoin is a scam because I have heard of any scam allegations on the exchange and everything is running smoothly when using the exchange. You should know that in every exchange, there will always be p2p traders that will likely want go scam you if you fall for them. That doesn't mean that it was Kucoin exchange that is the scam because if they find out such person, his account will be banned. You should also note that Kucoin is only an exchange where you buy and sell crypto pairs or use for p2p trade converting your cryptocurrency to fiat and not a wallet to store your assets. If you are planning to buy bitcoin, it's good that you use an open source noncustodial wallet like Electrum or Blue wallet to store your funds for safety.