Short Answer: The CandiensCanadiens were tired of war and content with British rule.
5.) Patriot attacks on CandiensCanadiens solidified opposition to the American revolution. American Patriot generals Richard Montgomery and Benedit Arnold Attacked Quebec in an attempt to seize Canada from British control (1775). They took Montreal and laid siege (ultimately unsuccessfully) to Quebec City, where British regulars and a few Candien militia defended. The Americans were ill-supplied but stayed till spring, when the British navy sailed up the St. Laurence.
6.) Economic Interests: The merchants of British North-America benefited from the influx of British troops (and money) which powered the offense south from Quebec. The CanadiansCanadiens also profited from access to the tariff-protected British markets, which far larger New England competitors had forfeited through the act of war. The fur market in particular began to thrive in Canada. The British Navy on the Atlantic and by British military power in the interior both guarded the fur trade.
As for the mass of French CanadiansCanadiens in the province (of Quebec), they began to follow their seigneurial and clerical elites into their own commitment to the British side. Naturally the Canadiens still put their distinct community concerns and heritage first; yet they also concluded that the Americans should not be welcomed, but kept outside. The self-proclaimed republican "liberators" had simply turned out to be the same old enemies, les Bostonnais, the Puritans of New England: stabling horses in Catholic churches during their invasion, paying in worthless paper money for crops and supplies seized from habitant farms. The Canadiens did not learn to love their British conquerors as a result -- why should they? -- but did grow to believe that they were better off with them. For the provisions of the Quebec Act had guaranteed French Canada's own special rights and character under British rule: guarantees which the Americans certainly would not have given. Instead angry American outcries had greeted the Act because of the very grants it had made to the "French Papists". Thus for different but historically sound reasons, neither the Francophone and Anglophone communities of Quebec province took to the American path of revolution. They stayed within the remaining British empire -- above all, to avoid being swallowed up in another emerging empire, that of the United States.