I completely agree with you on that. MC was guilty of not even trying to identify herself with the people. Marie Antoinette had good intentions, but too lazy & dumb to reach out to the public. Only Maria Amalia appear to realize the importance of this, yet she was also exiled like MC...
I seldom read anything - not much of it, even at Acton's book - that Maria Carolina was truly concerned with the Neapolitans or Sicilians. Acton wrote about the king and queen's good reforms for the last 30 years (I guess he counted a few years during Ferdinand of Naples' minority) but failed to elaborate on such reforms, save for the colony that was made into a silk production center (sorry I forgot the name). The navy was mentioned but I very much agree with the critique elsewhere that while a navy was essential, it was far too grand and costly for Naples.
As for Maria Carolina & Marie Antoinette, they were far too self-absorbed (in their "dramas") to "absorb" the undercurrents that surrounded their people. Maria Amalia was rather good at that, although I'd be the first to say that she had her many, many "dramas" as well. It does show though that she had the capacity to go beyond herself and her dramas, unlike her two sisters. With Marie Antoinette, it seemed to be self validation though her (physical) vanity while MC opted for a self validation by mental/power vanity. Well, Maria Amalia did go into exile but she wasn't exiled by the people, she decided on it herself - knowing what was to come from the French (Parma was to be absorbed by France because of the Treaty of Aranjuez and with the French announcing that they didn't recognise her regency). A very big difference with MC (exiled by her husband at the 'order' of a certain British official, and she was deeply unpopular with all classes by then). France only announced that Parma was part of its empire after Maria Amalia left, not as soon as Ferdinand died. Which tells us something about how Ferdinand and Amalia were regarded by their people.....