score:6
As a non-expert I would guess that:
a) It is hard to study without much of written sources; one can tell if an inscription is in Greek, Latin or what but it must be much more conjectural whether an excavated group of huts was occupied by Thracian speakers or some other group.
b) As Thracian and Illyrian were later replaced in most of the Balkans by Slavonic languages, most modern inhabitants of those areas feel less connection to (I say less connection to, I do not say none) and desire to preserve the memory of those cultures. (Albanian may be descended from Illyrian but Albania is a small, poor country with limited resources.)
c) As far as I know, the Thracians and Illyrians mostly failed to burst into other nations' histories to compel attention in the way that say the Goths and Vandals did when they overran large parts of the Roman Empire.
Upvote:1
The reasons may have been political, thereby resulting in the countries "fragmentation".
After the Romans conquered Illyria in the second century BCE, they subdivided the province into two shortly after the birth of Christ because of revolts in the area. After the fall of Rome, Illyria fell under the successive jurisdiction of Roman Catholic popes, and Byzantine rulers. These back-and-forths appear to have diluted "Illyrian" culture.
A similar story took place with Thrace, with was also repeatedly subdivided, particularly in the Middle Ages, into Turkish, Bulgarian, and Greek spheres. This kind of subdivision prevented the development, or at least the appearance of, a coherent "Thracian" culture.
So why are they not studied as much as other Balkan cultures? Because there is less available to study (in one piece), particularly because these cultures weren't good at keeping records to begin with.
Upvote:4
Timothy has raised valid points. Here are a couple of other suggestions: