^ I am fairly sure that there aren't huge business communities in Tremblant or Thunder Bay or Quebec City.
Beyond that this view is simply ridiculous and a straw man. Yes, Porter caters to business travelers. But on any Porter flight you'll have tons of averagely compensated civil servants, students, and vacationers. Not every traveler to New York or Chicago is a financier dressed in Armani. It's ignorant to suggest that just because Porter connects major urban centres that automatically means their customer base is almost entirely business travelers. Have you never vacationed in a major urban centre? Heck, believe it or not, there are a number of us who have never been to Florida, Vegas or the Caribbean (myself included) but on occasion will travel to Chicago or New York to visit family. Does that make us privileged?
It's a straw man argument to suggest that because there are low income people who don't fly often or only do so to visit relatives that we should not improve infrastructure for an airport that serves people with an above average income. By this argument, we should severely limit any sort of improvements that help Westjet since it doesn't serve too many foreign destinations. And if you believe this argument, then why only for an airport. I suggest that transit service, garbage pickup and road works should be scrapped to all wards with above average income. I also particularly resent having to contribute to the 2.5 million dollar tab for ferry service to under a thousand residents on the Islands. Why should the city pay for that privileged group but not travelers (business or otherwise)? The 30 000 in your hypothetical scenario is still about 30 times larger than the number of Island residents. Yet it's somehow fair in your books to offer them a service with an annual recurring cost of $2.5 million while not spending $38 million on a one-time tunnel construction project. Can you share with us, your definitions of "privilege" and "fairness"?