The ottoman government deported the Armenians because they thought that Armenians were trying and were involved in building their own state during the Ottoman Empire.
Explanation:
The Ottoman Empire was becoming less powerful due to the diverse religion and ethnic groups so they wanted to create a territory with single ethnicity and religion.
But Armenians were not agreeing these steps from ottoman which resulted in the suspicion that they would create their own state. So, the genocide over Armenians outraged.