On-time performance is truly a YMMV situation. Averages don't matter if the flights YOU take are regularly late. A gate agent at LAX once told me that she wished WN would drop the 4:30PM flight to OAK, since it was so late so often. I imagine that the scheduling people will eventually change routings to fix this, but repeated poor performance on a given flight has convinced many a passenger to switch airlines. When it comes to this subject, people pay more attention to their own experience than to network-wide averages.