While Muslims may not have objected to their daughters being sent to a harem in Turkey, the Christians certainly didn't want that for their daughters. Nor did the Christians want their sons ripped from them, sent to Turkey to be brainwashed and sent back to terrorize them!
"Terrorize" them? One of them restores the Serb patriarchate in 1557. Some "terrorizing".
To be sure, the Serbs were then the Otomans' faithful allies, and were rewarded by wide-ranging privileges given to their church.