So I just listened to Why for the first time.

[Macfan4life]

Why live during 1976 is a deeply powerful song. The harmonies are the best ever.
I wish they would have time to play it live on this tour. But look at some of the comments on this board bashing the Mac for playing "I know Im not wrong." and say people walk out and just because people don't recognize it, it should not be played.
I suspect many would feel the same way and want the hits.
I would prefer to hear Why than Songbird at the end.