As so often happens, the geography of a country, state, etc. is inextricably connected to its history. So, in addition to the factors so well addressed in the previous post, Nova Scotia's geography also contributed greatly to its non-involvement in the Revolutionary War. In his book, Neutral Yankees of Nova Scotia, historian John Barlet Berber contends that because of the geographical nature of Nova Scotia, it had no choice but to remain neutral. For one thing, settlements were scattered along the extremely rough terrain which defied the construction of roads, so he equally rough waters of the Atlantic were the only outlet for travel. Given these physical conditions, the Nova Scotians had little choice but to stay out of the war.
Besides the prohibitory nature of the geography, there were some Scots in Nova Scotia who remained loyal to the British crown along with the influential British who were loyal Added to this fact, many of the settlers were new to this settlement and had friends and relatives still in England, so their loyalties were still closely connected.
You would think that Nova Scotia would have wanted to join the American Revolution. The colony had originally been French but was taken from the French by the British. The French population was expelled from Nova Scotia and the colony was then populated mostly by people who came up from New England which was, of course, the hotbed of the Revolution.
The most likely reason why Nova Scotia did not join the American Revolution was the fact that the British had it more tightly controlled than the 13 colonies were. Halifax was a major British naval base and would have been a military threat to Nova Scotia had it tried to rebel.
In addition, the economy relied much more heavily on the British because of the presence of the large base. This meant that the richest men in the colony were connected by ties of business to the British authorities.