Premise: Bakhtar Afghan Airlines was an airline from Afghanistan, which offered domestic flights. The company was founded in 1967 as Bakhtar Alwatana, a name it kept until 1985, when it was renamed Bakhtar Afghan Airlines. In 1985 the company absorbed Ariana Afghan Airlines and became Afghanistan's sole airline company. In 1988 the Ariana and Bakhtar brands merged.
Hypothesis: It was renamed because it was hard for people to pronounce.