Simplifying a Chiro to just subluxation "popping" is rather...limited. I mean, why would we go to 4 years of med school for that? The act of adjusting--a monkey could do. The act of diagnosing is where our skills come in. We specialize in functional neurology, and more often than not that causes direct muscular change and facilitation. In order to rehabilitate the nervous system, often too we have to deal with muscles directly and are definitely more qualified than a PT in that. The way I see it, we work on a higher order 1st (higher as in neurology to muscles, not a statement of better or worse) and thus clear problems that a PT is not trained to deal with much quicker and better.
Thus said, for certain problems--usually in rehab and muscle atrophy/damage, PTs are absolutely necessary. We each have our specialties, modalities, and should respect each other for that I have no problem with. Also, there is of course overlap in some areas, some grey-zone which is to be expected (different ways of working on the same body). But for a problem like stated above, it is absolutely chiropractic in nature on all levels. Not just some.