I have never used wifi on an airplane. I can imagine that I might want to use it sometime in the future, but it is expensive and not all that easy to use. This paragraph probably captures the reality very nicely:
In-flight WiFi is basically the worst. To get online at all, you usually have to run the gauntlet of a complicated transaction page, typing in your credit card number or performing some kind of log-in. Then you have to fork over three or four coffees' worth of money just so that you can get speeds that rival your parents' dial-up Internet.