FWIW, the Loyalists weren't traitors. Anyway, many of them weren't. They were merely Americans who stayed loyal to the King when their neighbors chose to change their allegiance and rebel. As the Loyalists had sworn no allegiance to the rebel cause, it was not possible for them to "betray" it.
Their situation is much more analogous to that of the many southerners who remained loyal to the Union when a majority of their neighbors decided to secede. They were a majority in many areas, notably WV and other mountainous areas of the Confederacy. Similarly, Loyalists were probably a majority in several colonies, particularly NY and GA.
Whether secession constituted rebellion or not was the primary factor over which the war was fought. Men of honor have disagreed profoundly, then and now, about whether states had a right to secede. You have every right to believe that they did, if you wish, but their right to do so is not a fact, it is an assertion.
The South chose to assert its right to secede on the field of battle rather than by using legal or constitutional means. It is poetically just that war proved them wrong.
Let me ask:
How would you have had them secede? The states called for secession conventions, and in most states, the actions of these conventions were ratified by popular vote. In my state of Texas, secession passed by an overwhelming majority. After this was done, the Confederates sent commissioners to try and meet to settle issues of property, etc. and were rebuffed by Lincoln. War was really the only honorable choice left to them.