One of the major grievances of the 13 colonies was the taxation to pay for the earlier French & Indian Wars, while those in Canada could perhaps more easily see the gains from that conflict. In addition, the dumping of cheap tea on the Massachusetts market, which led to the Boston Tea party, ruined the highly profitable New England smuggling business but probably didn't affect those up north. Again, treaties which the British had made with Indian, oops, Native American tribes, to restrict inland settlement, were fiercely resented by New Englanders, while in Canada the pressure of Western expansion was much less, and didn't really result in inter-racial conflict until the Metis uprisings of the next century... In any case, support for the rebellion was pretty marginal, with even people like John Adams(?) reckoning that the split was one third for, one third against and a third just wanting to get on with their lives...