Why do some businesses hire only assholes? To minimize service. Service costs money: if a business doesn't need to maintain good service, they will not only not provide good service, but will actively discourage customer complaints by hiring assholes. Got a problem with your phone bill? Too bad: they don't need your business. Got a problem with your TV cable? Too fucking bad: they're a monopoly, so screw you! Trying to make a claim from an automobile insurance company? LOTS OF LUCK, BUDDY!
Businesses who hire assholes know that the harder they make it for their customers to aquire services, the less money they must expend. This only works for businesses that do not need a good reputation: government offices, automobile insurance companies (in places where one must purchase insurance if one wishes to operate an automobile), and businesses that do not have competition: trash pickup, water, natural gas, electricity.
What can one do about it? Not a damn thing.