Well for some it's just an excuse to be part of the party. The Leaf players are advertised repeatedly, they are treated like demiGods in Toronto specifically but even well known around Canada and around the globe.
I'm old enough to have been in my youth when the Jays won back to back in 92 and 93. A million people were downtown walking the streets on game night. It was unmatched. Multiple women walking by hugging and kissing me and I know I'm not alone. It was a hell of a fun night and you couldn't get more people out there if we had just won a war.
Not everyone was into sports as my circle of friends were but everyone was a Jays fan that night and even the casual fan knew the players names.
If the Leafs win, it will make that insane scene seem mild, especially with this group as they have been together for a decade. I hope it occurs and I would envy those younger fans who will be a part of such a massive party on game night and any subsequent parade.