I'm ok with many exchanges, I don't want a few exchanges getting the monopoly of the market, if this happens, we have no control on decentralization and price will have an impact since these few exchanges can charge a very high fee, because of lack of options, we need more exchanges and each one independent of the other exchanges, the stronger the competition, the better for the community to benefit.
I agree, it will also prevent a big manipulation of the markets and having many exchanges will force them to improve their services and platform. Having few exchangers around will make them comfortable and wont keep on improving.
Having more competitions will bring something new to exchange owners to offer something that will be benefiting to the traders and investors.
With those new exchange that trying to gained reputations even offering much lesser fee or bonuses if they survived and get the trust from traders
it will force those big and existing exchanges to improve and to keep things favorable to their members/traders.
Aside from monopoly, competitions also bringing new sets of ideas for owners to create more features around their business.