And you assume that I'm a westerner. Montenegrin identity has existed since at least the 16th century, as the only area of old Serbia to not fall under heavy Ottoman rule. Its location on the Adriatic, and the mountains that no large army could campaign in, gave it a unique position between Adriatic and interior Balkan. That's what makes your statement untrue. Why else would some Montenegrins rebel against unification with Serbia?
They didn't rebel against unification as such - they rebelled against the deposition of the Petrovic-Njegos dynasty. Unification with Serbia
under the Petrovic-Njegos scepter was the primary political program for centuries, and the majority of Montenegrin Slavs before 1912 considered themselves to be one branch of a larger Serbian family. The divide in Montenegrin society was about the questions of dynasty and regionalism vs unitarism...which often amounted to the same thing.
So while Communists didn't create the Montenegrin identity out of thin air, they are what allowed it to expand and develop into its modern form.
Without Ottoman expansion, there might be
some separate identity in modern-day Montenegro, but it's going to be confined purely to a few Catholic communities living right along the coast. And they're not going to call themselves Montenegrin, but Diocleian, Illyrian or something else entirely.