Why should the Loyalists stay with the British?

There were plenty of reasons for the American colonists to stay loyal to the British:
For one thing, Great Britain was a leading military and maritime power. In a dangerous, hostile world, it makes sense to have protection, and the British were certainly more than capable of providing that.
Another reason is that there were so many similarities between the British and their American colonists—language, culture, education—that it didn't make much sense to want to break free from the mother country. Yes, there were problems, but surely they could be ironed out through negotiations and some kind of amicable settlement. After all, as both the British and their colonists shared a similar outlook, it really ought to have been possible to reach an accommodation instead of declaring independence unilaterally.
Independence was too much of a leap in the dark. Not only could it lead to war with the British, a war which the British would almost certainly win, it could also result in domestic political disorder, with bitter divisions potentially breaking out into full-scale civil war.
The American colonies had done very well economically as part of the British Empire. But if they went their separate way, then America's prosperity could be seriously jeopardized. After all, at that time America was a very loose collection of independent political units. How on earth could they be expected to come together into a unified trading nation capable of making its own way in the world?