Why did the Spartans stubbornly refuse to be a part of Macedonian or Grecian society?
Three reasons. Despite their responsible and hard-working military citizenry, they were keeping helot slaves in vast numbers and “dwellers round about”, serfs from previous wars, who hated them, in totalitarian castes. They could not give up gangster militarism toward other cities and they couldn’t be partners with anyone else; the contradiction lay in the fact that they had accepted responsibility as individuals but not as a political city in a world filled with other city-states, tribes and primitive kingdoms. The Spartans kept to their Draconian Way because they thought they had to to keep their slaves and serfs from rising against them.
The Spartans were no different to the other Greek City States. Don’t forget that there was no one country, just a collection of (very small by our standards) cities, all speaking the same language, or variations of it (the Ancient Greek we are taught is ‘Attic’ Greek, or that spoken in Athens). They weren’t necessarily friendly with each other – don’t forget that they fought each other, most notably in the Peloponnesian Wars – see http://en.wikipedia.