Letters That Incorporate Commentary From Other Individuals

We appreciate when a recommendation showcases growth so responding to a disappointing grade on a midterm or a paper by coming to weekly office hours requesting additional reading discussing concepts further. What's your take on letters that incorporate commentary from another individual? I have kind of mixed feelings about this if the primary letter writer is saying things independently and they have lots of great things to say about you independently. But if they don't have anything independent to say and it's just the quote,I'm always in my mind thinking well why didn't you just get that other person to write the letter?"