For the most part I do think it's a bad idea since you'll be leaking information especially if you're demanding liquidity, ie you want to get size done like with a vwap order, then exceptionally stupid. But if one is trading opportunistically then it can make sense. For example let's say you think there is non informed flow demanding liquidity and potentially causing significant temporary market impact due to that.. then displaying large size does encourage them to sweep the book and hit the order. It's a tricky game though because you do leak alpha information over time. Someone can effectively reverse engineer what you're doing and step in front of you. So I would note that is rather different than a spoofer. In this case the order is conditional on a short term prediction based on the probability of significant non informed flow. It's good liquidity and reduces market impact of long term market participants especially as competition increases to provide liquidity to them. I used to display large size 10 years ago for the above reason. But the short term game has gotten a lot more competitive with the end effect being that large displayed orders are more likely than not to be adversely selected when filled. I think that's largely because the game is more in residual space now whereas 10-15 years ago it was easier to create a decent short term model in equities with a single factor model or just raw returns.
Have we even established that NQ moves on it's own...it is an index of individual stocks after all. Certainly agree that MNQ isn't leading anything!