There are so many variables to this problem, but most of them boil down to GPS reliability. As a driver, I go to the designated pick up area, turn on my blinkers and wait, within one minute I send a text to notify rider that I'm there and blinkers are on. After 2 minutes if no response from rider, I cancel the pick up as a no show and proceed to the next one. This will be charged to the rider. There have been numerous occasions where my pick up spot is in the middle of nowhere, or there is no true area to wait. I will call, confirm and proceed accordingly. Another thing to consider is that not all drivers are familiar with the area and do not want to do a U-turn or risk getting a ticket. Personally, I do not cancel rides unnecessarily, and if I do, it is after I make an attempt to contact the rider and they still do not respond or show up. If I find myself in a situation when the GPS location goes bonkers on me I will cancel as a DO NOT CHARGE RIDER. I UBER in Chicago, and I avoid Wacker Dr, as for me it not always easy to determine if my pick up is in the upper or lower level Wacker Drive. A 2 minute pick up can easily become a 15 minute nightmare if I go on the wrong level. I prefer to avoid it. I recently had a pick where the ping was right in front of a bus stop during rush hour traffic, I went pass the bus stop and turn on my blinkers and notify rider as well via text. Cars had to go around me as I was right on the street, a few buses where heading towards me as well as a police car that signaled me to move on, the time was up and I canceled the trip as a RIDER DID NOT SHOW, as I proceeded to move here comes the rider towards me, I told her sorry, but I had to move, ride has been canceled you need to select another one.
There are some bad apples out there, I wont deny that, but before complaining, try to be on the other shoe and see what we also have to go through as well.