That’s like asking how the bank robbery went bad and turned into a shootout. It didn’t “go bad”, it was a bank robbery, it was already bad.
Islam hasn’t been hijacked. It’s never been a good thing for any land it infects.
With the possible exception of its Saudi Arabian homeland and even that is arguable. Before: It was practicing human sacrifice and was a land of brigands. After: It was a land which exported their violence elsewhere.
Persia. Before: A center of culture and art. The replacements for the fallen Roman Empire of the West.
Byzantium. Before: Shelter of the civilization of what remained of the Roman Empire. After: Center of the Turkish Caliphate whose main claim to fame was that it hadn't deteriorated as far as the rest of the Islam World.
Palestine/Lebanon/Syria. Before: Eastern outposts of Christianity and Judaism. Good mix of Byzantine, Roman, Persian and Judeo-Christian. After: An economic backwater where sites sacred to Jew, Christians and (supposedly) Muslims were allowed to deteriorate to near ruin, a process reversed only by the post World War I colonization by Great Britain and France and the 1948 founding of the State of Israel.
East Africa. Before: Backward, but peaceful. After: Still backward, but able to live off the successes of their neighbors by the introduction of the slave trade.