Why is there a need for different exchanges? In laymen's terms, why is there a need for different bitcoin exchanges? Is it currently the wild west and eventually these exchanges will consolidate. Or can exchanges actually provide different value to their customers, justifying their existence. I ask  this because there are 100+ exchanges out there? Why doesn't everyone just flock to the most reputable and liquid one?
Different countries, different laws, different currencies, different banks, different payment systems.

Competition and free market.

No single central point of failure.