Driving route from Toronto to Fort Lauderdale?

Why does every online website,aka: mapquest & map24.com all suggest a route from starting from Toronto and then going all the friggin way to Detriot, then south? Why can't I find a route that crosses near say Buffalo and then head south. It seems a hell of a lot more logical to go through the state of NY from Toronto instead of going all the way to Detriot as suggested by these web-sites. Hopefully it's not just because of the I-75 route being so common and straightforward that people would drive an extra 2-4 hours on what is already a long drive.