Because once you've ridden one taxi in NYC you know what the fare per mile will be every other time you ride, no matter the time of day or location of pickup, and you get a receipt showing you the price you actually paid.
"Is my electricity company being unfair because they offer discounts during low usage hours?"
I agree with your point. Here though is how a typical person thinks from what I have found and observed.
1) It's ok to offer a discount off the "regular" price for any reason. That's always a positive.
2) It's almost never accepted to charge more than "normal" or you appear to be "ripping off" or taking advantage" or possibly "gouging".
This has to do a great deal with people's expectations as far as "what is typical and normal" not so much with economic rationality.
For example if you went to a restaurant that had very fairly priced food but they charged you for the napkins you'd probably think that was "messed up". You wouldn't even really care if the price of hamburgers was 20% less than a competitor. All you would think is "wow that's screwed up look they are charging me for napkins!".
Now part of this also comes from many people who comment who possibly never have run a business ever and are consumers. Not that people who run businesses don't have their own thoughts. To that point I think someone who is narcissistic would tend to have a harder time with this than someone who is not. (Speculation on my part). Because they only believe that they have a right to make money not someone else.
I personally think it makes sense to charge more during peak times and when they can. That ends up subsidizing times (in theory) when they can't make money. And keeps them in business.
I do some consulting on the side. For arguments sake I should be charging, (let's say) $3000 for "$x" amount of work. However I get clients that can't afford that so I charge them (let's say) $1000. To make up for it I now have to charge some clients $5000 (because they can afford that and agree) and so the $5k clients end up subsidizing the $1k clients. If everyone had to be charged the same exact price I wouldn't be able to offer consulting at all because there wouldn't be enough customers at a fixed rate like that.
That makes the price knowable, I don't think that's the same as fair.
Lyft and Uber will both tell you if the price for the ride you're requesting will be higher than usual so in that sense their prices are just as knowable.
I think a fair price would be one that an informed and unencumbered buyer and seller reach. One reason why it can be hard to get a Taxi in New York if you're trying to leave Manhattan is because the prices aren't always fair and that drivers would rather seek a fairer transaction (in contravention of regulations).
