Bosnia joined their South-Slavic brothers in the creation of Yugoslavia. In 1992 Bosnian wanted their own independence even though 54% of the Bosnian population was either Serb/Croat/Yugoslav (1991 census: 1,366,104 (31%) Serbs, and 760,852 (17%) Croats, with 242,682 (6%) Yugoslavs)
Bosniak Muslims were a small minority in Yugoslavia(1981 census of Yugoslavia shows that Muslim Bosnians make up 8.9%) The majority of the countries land mass is Republic of Srpska(serb majority) and the southern Hrvat area(croat majority).
Most Bosniaks don't practice Islam as a religion but just use it to identify themselves. Most Bosniaks wear Western-style clothes and consume alcohol which is much different than the the true Islamic way.