Once enough negative associations form with the brand, it'll be the work of a generation to turn things around. Tracking user locations probably won't have a huge impact. Most people just don't care enough about privacy issues.
Tim Horton's real problem is that they are becoming known for bad coffee, bad donuts, and bad food, while similarly ubiquitous chains, like McDonalds, now have decent coffee and have added donuts to their menus. If I have to choose between a McDonalds burger and a microwaved chicken-finger with a shelf-stabilized tortilla wrapped around it from Tim Horton's, the choice is easy. Practically every truck-stop town that has a Tim Horton's also has a McDonald's very close by, so it really is just market inertia propping Tim Horton's up at this point.