This statement, repeated often by Geithner, is analogous to your boss insisting that he believes punctualityis integral to running a successful business, even as he engages in behavior that causes him routinely to be tardy.
Similarly, if invited for dinner at 9pm, showing up half an hour late is fine, unless the host specifically requests punctuality (in which case arrive around ten past).
It says Terminal 5 is consistently rated as one of the best airports in Europe, while plane punctuality and baggage performance have also improved and the average security queue stands at about two or three minutes.