I new someone would bring this up, not knowing the economic difference. Because WS is a lot smaller than AC and doesn’t have AC large presents in YYZ./YUL, their fleet doesn’t travel though these airport on a greater percentage.
AC has lots of Asia/Pacific and Europe routes that are not affected by weather that WS doesn't have, as a much great percentage of WS's routes are in Canada compared AC. AC is just chronically bad at scheduling and timkeeping.