A definition of insight is:
The capacity to gain an accurate and deep intuitive understanding of a person or thing.
So according to this, if you develop an insight for a person, it means you've developed an understanding of the person. And an understanding of someone can lead to acceptance? For example, would it be correct to say,
After refusing to accept Ben as his son for years, Jack finally developed an insight for Ben (and accepted him as his son).
Edit: Can you develop an insight for someone? After rereading, that part seems a little iffy.