As far as I'm aware, all of the major exchanges in the US are in NY or in Chicago, and even then, Chicago is mostly just futures exchanges for commodities and not stock exchanges. So unless you're headquartered in NYC (which most companies listed on NYSE/NASDAQ are not), you're already not working with a stock exchange in the same area as you, and failing to collocate the stock exchange isn't really a detriment. (Interestingly, even historically, when stock exchanges were more plentiful in the country, there just doesn't seem to have been much demand for a stock exchange on the west coast at all.)

The main reason to move away from the NYSE or NASDAQ is if you don't like the rules those stock exchanges have.