I think its better to have many exchanges for us to have many options. Competition is needed in order to have the best customer service satisfaction. These exchanges should offer the best for the market and in this way they cannot abuse for there are other exchanges to choose from. Traders will always find ways on where they can have an advantage.
What is the point in having a lot of (almost) identical exchanges? It only makes it harder. I'd prefer having less exchanges but each with its own features and level of fees so that I could choose according to my current needs.