A-Because they want students who have shown that they have grit or perseverance
Explanation:
The likely reason why colleges would want to admit only students who are passionate about their interest is because such students are committed to excellence in their chosen field. Because such students are passionate about what they want to be they do not easily give up when they encounter challenges in their academics.
They develop grit which involves courage, resolve, and strength of character that are vital for success.