I don't think that Slavic origins of Bosniaks need to be proved. ;) Some things are just fact. Language is just one of them.

Illyrians have not been mentioned anywhere since 4th-5th century, if I remember correctly, and Goths (other than Crimean Goths) also disappeared in Middle Ages.

I ask again, why must some Bosniaks feel this urge to label themselves as Illyrians and Goths instead of stronger Slavs, who conquered and assimilated this weaker peoples?

And also, why is this sort of this unique to Bosniaks, this whole Gothic origin whatever thing? There were large numbers of Vandals and Joms Vikings living in Slavic ureheimat Poland and large numbers of Goths and Varangian Vikings (probably more than amount of Gothic settlers in what is now Bosnia), yet when does one ever hear of Poles or Ukrainians claiming to be Germanic-originated people?

As to Illyrian thing, guess what? In Slavic ureheimat Poland, original inhabitants were Sarmatians and Prussians while in Slavic ureheimat Ukraine, original inhabitants were Cimmerians and Scythians. When does one ever hear Poles or Ukrainians claiming themselves to be any of this now extinct European tribes?

Bosniaks should be proud to be part of great Slavic world, rather than trying to escape to some dead ethnicity which indeed makes up element of their roots, but then again, how is that different from any other European tribe, given ancient migrations since 10,000 years?

It is stupid politics. Nothing more. Bosnia is Slavic nation and Slavic people. End of story.