Why don't banks give credit where it is needed?

Claire is a 32-year-old mother and the wife of a fund manager at one of Hong Kong's biggest banks, but when she hands her credit card to a waiter after a meal, she never knows if it will be declined.

via Business feed http://www.scmp.com/business/money/spending/article/1131041/why-dont-banks-give-credit-where-it-needed