You're assuming that everyone traveling to Toronto is from Toronto. It's easy for us, because we know it exists and where to look. For people coming from outside of Toronto, it hasn't been easy.
Judging by the ridership numbers, it seems like many are keeping away. When cabs are waiting within spitting distance of the arrivals exit, of course someone is going to choose one right away over looking around for the UP terminal. (Which is why he ended up in a cab instead... it was waiting right there)
There are many airports with much better signage than ours that we can learn from. Madrid's Barajas airport has an amazing system that is clear and intuitive, Heathrow has their signage in bright colours that stand out easily, making them no trouble to find, and even YVR here in Canada has signs along corridors that people walk through pointing you to the train from arrivals. Heck, even Shanghai does a better job of directing you to the trains.
I walked out of the International doors a month ago, looking for my wife and not the train, looked up and immediately saw the 'Train to City' logo. I remember thinking at the time, "What's with all the fuss about signage? It's right there with everything else."
Also, unless it was 3am or something, there's a CIBC kiosk to ask and the actual ticket sellers booth (IIROC) all within 50m of the international entrance.
There was also, as I walked in, a temporary booth from University of Toronto greeting international students, a different booth doing the same for other international university students, and about 300 people there to greet travelers, any of whom your friend could have asked.
Choosing a cab because it's right there is a choice of ease. And maybe the UP folks underestimated how many people will take a cab when the cab's paid for, even if the roads are complained about incessantly. Maybe the real issue is that, despite the incessant whingeing from car users, our highways are not so bad that they will actually change their behaviour. That may be a real blow for UP -- that they listened to the carping and didn't properly model the actual usage.
In that case, those folks wanting UP to be as cheap as the TTC might get their long-term wish, as the UP might actually become a commuter train to Pearson, at least during rush hour.
I'm still agnostic. I think UP will have a great deal of appeal in the cold winter months for business people going from PATH-linked buildings to Pearson, and I would have thought vice versa but maybe incoming business passengers are so used to grabbing a cab they'll need a huge Heathrow-style push to start using the train. (Which I think should be done, anyway: three UP ticket sellers on commission and the usage triples overnight.)
