Once the iPhone app starts invoking a "Facebook would like to use your current location" popup each time you launch, where "no" will prompt you again next time,

Once the iPhone app starts invoking a "Facebook would like to use your current location" popup each time you launch, where "no" will prompt you again next time, but "yes" will remove the annoyance, a lot of people will choose the latter. And then some people will uninstall it.