Do not forget that many new projects are coming into crypto space focusing only on the funds they will raised through IEO/ICO
what exactly are you saying in essence? that all low rated exchanges are possible scammers, you could be right or wrong as this is just base on your personal assumption and nothing else, many project go for the low rated exchanges because they are more affordable and their conditions are more flexible than that of the high rated money milking exchanges, what is the benefit of given almost half of the worth of your project to a high end exchange when you can get similar services for less
Those who list on low end exchange know the reason why.