Well, they're legally required to. The reason that taxi fares don't vary is not that nobody until Uber had ever thought of varying meter rates. It's that, in

Well, they're legally required to. The reason that taxi fares don't vary is not that nobody until Uber had ever thought of varying meter rates. It's that, in developed nations at least, the government imposed a regular rate, largely in an attempt to forestall situations where there is real or perceived gouging of customers. The idea is that nobody could possibly be expected to maintain in their heads different meter rates for every taxi company in town, much less if those rates vary at times of days, and that you didn't want to compel people to jump in the car and then bargain with the driver (as is done in much of the developing world) or otherwise investigate the rates. Uber's solution of advertising a multiple that you must very explicitly agree to before hailing is, don't get me wrong, a very elegant solution to the problem. But it's not as though they came up with the idea of variable rates for rides-for-hire.