This one star review is to draw attention to an issue with their backcountry reservation system.
Many backcountry campsites in Jasper you need to reserve 6 months+ in advance, so naturally a lot of people's plans change in that time, and they can't show up. Since these are high-demand sites, the "right" thing to do is to cancel your reservation so that someone else can use it. Unfortunately, Parks Canada charges an $11 "cancellation fee" to cancel, in additional to forfeiting your "$12 reservation fee" (which is on top of the site fees). This fee is actually more than the $9.80 it costs for a single night booking, so in theory it would cost you more money to cancel a 1 night booking than to just not show up.
This leads to a lot of people not being able to take trips that they would otherwise have the opportunity to. When I did Jasper's Skyline Trail on a Long Weekend, I was the ONLY person at one of the sites I stayed at, even though the site was booked out. I was annoyed that 7 other groups hadn't made cancellations to open the sites for others, but now I understand that it is a Parks Canada policy that is at least partially to blame.
Considering that you lose your $12 "reservation fee" regardless, there is no need for an additional $11 cancellation fee.
Another good policy change would be to have some sort of "check-in" system a week or a month in advance, because I bet some people just forget.
So remember, if you can't get your back-country reservation, remember that it isn't necessarily high demand that is getting in the way - it may just be good old fashioned mismanagement.