Tim Horton's heavily marketed themselves as something patriotic, and it stuck. Lots of heartstring-pulling ads about soldiers and Olympians and backpackers abroad jonesing for Tim's and having melodramatic homecoming family moments with a cup of coffee in-hand. Canadians aren't really bombarded/innoculated with patriotic imagery the way Americans are, so this didn't get the kind of eye-rolling reaction it deserved.

See also Canadian Tire, which is basically Wal-Mart's hardware section after it invaded and took over the whole store... somehow buying duck-tape and WD-40 from a confused teenager is patriotic too.