Does CoinBase and or BitPay handle the British Pound?

I think the reason is both legal and the ability to convert the currency to the company's country fiat. Make no mistake these companies accepting BTC are not holding BTC.
This. Although there are a bunch of exchanges that let you use a wide variety of currencies, there aren't many (if any) mature payment processors that convert to something other than USD. There needs to be a pound/euro/etc payment processor that plugs in just like visa/mastercard/paypal that is mature enough for a big company to trust.