For example Creditcoin which is only listed on OKEX and Bittrex from my understanding it is very hard to list on those exchanges if its a scam
would you say that is correct?
They can also list scam coins in that exchange. I remember one of scam coins i have listed only in okex ,but they are also one of the trusted exchange i use .
Open a scam accusation in different exchange is normal here. The review will only depend on you as user's and on your own experience using it.
As for my review i never experience any problem using that exchange even delay in transaction is not problem. you will also recieve a notification on your email every time you widraw or deposit any currency that exchange.