I don't get it. Doesn't every airport in the world have taxis waiting. Why would you need an app to get a taxi at an airport.
Uber isn't right for every use-case; especially pick-ups from regulated areas where taxi stands are already prevalent.
The only downside is that there's a short wait if I don't time the ride request just right. Since there are tons of taxis at the airport, I wouldn't have to wait taking a taxi. But the above more than makes up for this point.