Why Macedonian Slavs Stealing the Greek Macedonian History?

Historian and Professor Eugene Borza who is credited as "Macedonian specialist" by the American Philological Association, and who have done extensive studies regarding the ethnicity of the ancient Macedonians, had also presented in-depth analysis that the ancient Macedonians were not "Slavs" or mixture of Slavs and Romans as Macedonian Slavonic position claim.. In his Macedonia Redux Borza writes:

The Macedonian kingdom was absorbed into the Roman Empire, never to recover its independence. During medieval and modem times, Macedonia was known as a Balkan region inhabited by ethnic Greeks, Albanians, Vlachs, Serbs, Bulgarians, Jews, and Turks.

Without a common national entity and distinguished historical path, as a nation, the present fYROMacedonia was part of Serbia since 1912 with the name of VARDARSKA and with Skopje as its capital. In 1929, following an administrative reorganization of the "Kingdom of Serbia, Croatia and Slovenia", which consisted of 33 Districts (Oblasti), the "Kingdom of South-Slavia" (Yugoslavia) was created, with 9 Administrative Districts (Banobina) and a 10th one, independent, the Administrative District of Belgrade. The boundaries of the 9 Districts where set with geophysical criterias, in a way that they did not disturb any ethnological elements. Due to the inborn ethnological problem of the entire Dominion, which was composed of a mosaic of nationalities, the reformation law had foreseen the non existence, for each of the administrative districts, of common ethnographic elements, which could incubate future moves for independence. Thus, the present lack of ethnological homogeneity of the state of fYROM, is the result of diligent work and not incidental. The non existence of homogeneity is due to this prudence.Loring Danforth point out:

The history of the construction of a macedonian national identity does not begin with alexander the great in the fourth century b.c. or with saints cyril and methodius in the ninth century a.d., as Macedonian nationalist historians often claim. nor does it begin with tito and the establishment of the people's republic of macedonia in 1944 as greek nationalist historians would have us believe. It begins in the nineteenth century with the first expressions of macedonian ethnic nationalism on the part of a small number of intellectuals in places like thessaloniki, belgrade, sophia, and st.petersburg. this period marks the beginning of the process of "imagining" a macedonian national community, the beginning of the construction of a macedonian national identity and culture"

The fYROMacedonian historiography basing her “stealing process” via the Historical revisionism.Historical revisionism is the attempt to change commonly held ideas about the past. In its legitimate form (see historical revisionism) it is the reexamination of historical facts, with an eye towards updating historical narratives with newly discovered, more accurate, or less biased information, acknowledging that history of an event, as it has been traditionally told, may not be entirely accurate.Historical revisionism can be used as a label to describe the views of self-taught historians who publish articles that deliberately misrepresent and manipulate historical evidence.

This process identified from the Bulgarian historians as Macedonisn. Macedonism is the political idea prevalent in the Republic of Macedonia advocates revising history in order to project an ethnic group that formed in the 20th century - ethnic Macedonians - in the context of the 19th century and even in the middle ages. For example, Bulgarian Tsar Samuil is denied the Bulgarian nature of his kingdom, despite overwhelming evidence supporting it, and is defined as a "Slavic" or "Macedonian" king. Further attempts are made to deny the Hellenic nature of the ancient kingdom of Macedon and to seek connections between present day ethnic Macedonians and the Ancient Macedonians.What are the aims of the Macedonists after the creation of the Macedonian Slav State ? Maria Nystazopoulou Pelekidou writes:

Their first aim was to cut off every link between the so-called "Macedonians" and the Bulgarians, as a well as the Serbs, and to convince the people that they belonged to a separate Slavic nation, the "Macedonian" one

The second aim was to eliminate Greek character of Macedonia and Macedonian history; and this would be achieved by minimizing the Greek presence in this region and misinterpreting or falsifying their role, specifically the cultural and intellectual contribution of Hellenism, the orthodox Greek clergy and Greek schools.

The third aim was to search for, fabricate and project the historical development of the so-called "Macedonian people", so as to prove the separate national identity of the "Macedonians", as well as their cohesion and continuity from ancient times until today.

The fourth aim was to create a Great Idea, which would bring awareness to the masses. So the historians of Skopje started declaring that Macedonia, as a whole, was a Slavic country both in its historical tradition and its ethnic composition. For this reason, it had to be united and form a unified state.

That is exactly why the Macedonian Slavs claim that the ancient Macedonians "were Slavs" or Mix, so that if in ancient times there was a non Greek tribe (Macedonians) living in Macedonia, then that land therefore is non Greek and therefore with the Slavonic invasion in 6th cent these Slavs didn’t find any Greek presence. They exterminated a large number of the indigenous population and assimilated the rest. Thus, within a few years Macedonia became Slavic. Because these indigenous populations were Illyrian and not Greek, the Slavs who settled in Macedonia were united with that non-Greek element and thus acquired ancient roots, irrespective of any Greek presence. In this way, Skopje claims for itself not only the history but also the achievements of the civilization connected to this region.

Source
1-Eugene Borza, “Macedonian Redux”
2-Loring Danforth, “The Macedonia Conflict”
3-Maria Nystazopoulou Pelekidou, “The Macedonian Question”
4-Historical Revisionism, wikipedia