Thank you for the clarification. Presumably if you have to clear US customs then you also have to collect your checked baggage at the US hub, schlep it through customs, then recheck it. By contrast if you fly out of Pearson you can check your baggage there and pick it up at your overseas destination.
You also have to go through a US physical security check. This is sometimes stricter than elsewhere so even if your nail clipper (or similarly benign item) could have travelled in your carry on between Canada and overseas it might get confiscated in the US.
And you alluded to the "special" welcome that the US provides to those passengers that they suspect may have ill intent. (Granted it was an exceptional case, but I imagine Maher Arar would not be a household name if he'd flown directly to Canada.) I know other people from alleged "terrorist" countries who avoid going to the US at all costs.
In any case and for whatever reason(s), going overseas from YKF through a US hub is more inconvenient and/or impractical in all too many situations than departing from YYZ.
This is yet another reason why for me better ground transport options between RoW and YYZ is far more important than more international flights out of YKF. I appreciate that's not what fans of YKF want to hear. But that doesn't make it any less a reality.
You also have to go through a US physical security check. This is sometimes stricter than elsewhere so even if your nail clipper (or similarly benign item) could have travelled in your carry on between Canada and overseas it might get confiscated in the US.
And you alluded to the "special" welcome that the US provides to those passengers that they suspect may have ill intent. (Granted it was an exceptional case, but I imagine Maher Arar would not be a household name if he'd flown directly to Canada.) I know other people from alleged "terrorist" countries who avoid going to the US at all costs.
In any case and for whatever reason(s), going overseas from YKF through a US hub is more inconvenient and/or impractical in all too many situations than departing from YYZ.
This is yet another reason why for me better ground transport options between RoW and YYZ is far more important than more international flights out of YKF. I appreciate that's not what fans of YKF want to hear. But that doesn't make it any less a reality.