This statement is largely false.

As explained in detail in the wiki above, there are several ways to ride the 747 bus. One of them is to purchase a single-use, two-hour ticket from a Stationnement de Montréal parking payment kiosk. But that's offered as a convenience among other options; nobody is required to buy a two-hour ticket.

All of the following passes are also accepted on the 747:

• 1-day
• 3-day
• unlimited weekend
• weekly CAM hebdo
• 4-month CAM
• monthly TRAM 1 to 8

Thus, a regular STM rider will incur no extra cost. And short-term visitors can buy a one-day pass the day before departure; for $10, you get your ride to YUL on the 747 on top of a day of unlimited in-town trips.

EDIT: I'll spell this out even more clearly. For $10, a short-term visitor gets a) unlimited in-town STM rides for the last 24 hours of his/her visit, plus b) a ride to the airport. It's what I did on my last visit, and it's just as much a bargain as buying the pass for use coming into the city from the airport.