Blown highlights might be in a part of the scene that I don't care about, or reflections from a flash that can't be avoided.
This is not a great example, but the best I can find now. (If I can find a better one I'll put it up.) If I reduce exposure so the sun is "properly" exposed, the rest of the photo just about vanishes.
I take the opposite of that photo all the time, when I try to get a moon photo. In that case, I want the moon to be properly exposed and I'm less concerned with the sky. The meter ignores the moon unless I use a
really long lens (1000mm) to make it large in the scene. So I have to underexpose to get a typical moon photo.
Another example (bad photo, good example) is an indoor shot under natural daylight, with a window in the frame. My *ist DS chose to meter this scene to preserve some window detail:
You sort of have to pretend there's an important subject here to make this a valid example.
But if there was, it would be better to properly expose the subject than the window view. I overexposed here, blew out the windows and got betteer exposure of the room.