Are you crazy man?
Macedonians used to be Serbians....hahahaaa
And to ask you something:
If they were Serbs why they speak a Bulgarian dialect?
Those dialect received the status of a language but it doesnt matter..
Just look at your mother tongue -- Serbian.
It's not a language at all.
Serbian,Croatian,Bosnian and Montenegrin are just different dialect of one and the same language. (it's funny to claim that Montengrin exists but I feel the same way when I hear this for Macedonian

)
Here's the source --
http://en.wikipedia.org/wiki/Slavic_languages
Look the info.If you dont believe just look anywhere to find that Macedonian is closer to Bulgarian ..and even some linguists claim that this is one and the same language.
South Slavic languages:
Western Section
Slovenian - (SIL Code, SLV; ISO 639-1 code, sl; ISO 639-2 code, slv)
Serbo-Croatian - (SIL Code, SRC; ISO 639-1 codes, bs, hr and sr; ISO 639-2 codes, bos; ISO 639-2(B) codes, scr and scc; ISO 639-2(T) codes, hrv and srp)
After the break-up of Yugoslavia they became officially considered as three languages, Serbian, Croatian, and Bosnian, though the differences (apart from the choice of script) are more political than dialectal. For more information see Differences in official languages in Serbia, Croatia and Bosnia.
Romano-Serbian - (SIL Code, RSB; ISO 639-2 code, sla)
Eastern Section
Macedonian - (SIL Code, MKJ; ISO 639-1 code, mk; ISO 639-2(B) code, mac; ISO 639-2(T) code, mkd)
Bulgarian - (SIL Code, BLG; ISO 639-1 code, bg; ISO 639-2 code, bul)
Old Church Slavonic - extinct (SIL Code, SLN; ISO 639-1 code, cu; ISO 639-2 code, chu)
It is perfectly clear that the so called Macedonian and Serbian are each in different language subgroup.
and read more:
http://en.wikipedia.org/wiki/Bulgarian_language
"Bulgarian demonstrates several linguistic innovations that set it apart from other Slavic languages, such as the elimination of noun declension, the development of a suffix definite article (possibly inherited from the Bulgar language, or taken from Albanian), the lack of verb infinitive, and the retention and further development of the Proto-Slavic verb system. There are various verb forms to express non-witnessed, retold, and doubtful action."
Serbian and Bulgarian/Macedonian are close languages but very different in linguistic view.
Any Objections???