Not just Ontario, common at with many public park systems.
The fact is the parks are very busy and people struggle to get reservations. People treat it kind of like doing your taxes. If the system accepts it, people will do it.
I do think there are things they could do to minimize some of the games but I'm not sure how much political will there is to fix the problem.
- Limit reservation modifications. In particular the start date. Because the systems open reservations X days out, people figured out, book X+7 days before the start of a holiday weekend and you get in before people doing a legitimate booking for the holiday weekend. Maybe change it so the arrival date can't be changed by more than 2 days without making a completely new reservation (assuming there are available sites). That would address 99% of legitimate changes but reduce the majority of people gaming the system.
- Some people will simply pay for extra days to get a popular weekend. Public parks tend to be lower cost, so if the alternative is no site, they may be willing to pay an extra $100-150 if it gets them the site even if they don't use those nights. I'm not sure if it's still the rule but for Michigan state parks, it used to be, you had to have the RV (or tent) in the site and you had to stay overnight. That largely took care of this issue because if you didn't show up, you lost the reservation.
