DUG NPS. What's the point?

I don't work in DUG but I can log in to the handheld device to hand off orders. Any time I hand off an order I give the customer some free items from a box in the DUG room and ask the customer to please do the survey and give us a 10 if they believe we earned it. Sometimes it works, sometimes it doesn't. I only started doing that because my manager told me to any time I hand off an order.

Earlier there was a DUG meeting and my manager brought everyone into the office and was complaining the only person who got us DUG NPS survey the day prior was me.

I was just listening but I don't fully understand. What's the point of DUG NPS? Does the DUG employees get more hours the higher their NPS is? Does the store get more money? Or is it just a number that DMs can pat themselves on the back for?

I can understand customer complaints (IE so and so isn't picking the best fruit or was rude handing off an order) but why does getting 100% NPS such a big deal?