Answer: The reasons for the Greek view of the Macedonians is pretty simple. They kind of were a bit backward. Now when I say that what I mean should be very clarified. First of all, there are actually two Macedonias, Upper and Lower Macedonia. Lower Macedonia is mostly the coastal region and it's separated from the Upper Macedonian highlands by a ring of mountains, through which there are only a handful of passes. Upper Macedonia was inhabited almost entirely by non-Greek speakers, mostly Pannonians and various groups related to the Epirotes, Molossians, and Illyrians. Throughout the history of the Macedonian state the upland barons owed some sort of allegiance to the lowland rulers, although just to what degree varied pretty significantly. To the Greeks, and even to the Macedonian rulers, these people were very much barbarians
I hope this helps
~Princess <3