I think that is beside the point. If I'm understanding the author clearly, the only thing he knew before the ride completed was that there /was/ a surcharge, no

I think that is beside the point. If I'm understanding the author clearly, the only thing he knew before the ride completed was that there /was/ a surcharge, not the amount he would have to pay. It's difficult to do a cost-benefit analysis without knowing the cost up front. I agree, if I saw that I'd have to pay 20 dollars more than normal because it is a holiday, I'd choose to pay it, but there's a certain threshold that I wouldn't cross and uber seems to be (again, if I understand the author correctly) intentionally hiding the surcharge from its users to avoid the possibility of users deciding that the surcharge would put the price above that threshold.