Healthy markets function by consumers supporting things they like.

This isn't that sort of market. You're getting influence over inflation that doesn't come from your own stake, it comes from all stake. You're not a "consumer", you're a participant in shared decision making.

For this to make economic sense it has to also benefit all stake. If the other stakeholders don't agree that what is being paid out benefits them, you can't have unilateral decision making over that shared resource.

You CAN certainly support what you want as a consumer with your own money. That works just like any market and can't be downvoted.

However, when the whitepaper speaks to negative voting, it only says that it is possible, it does not say that it is "VALID."

It says more than possible. It also explains why it is needed: For significant cases where rewards do not add (enough) value, while also noting that not every single little instance needs to be stopped (which I agree with).

Also, it kind of matters that the original system had superlinear rewards. You needed to get a LOT of stake voting in order to get significant rewards. A small amount of staking trying to vote where others don't agree would accomplish nothing (tiny or no payout). That had good and bad elements. When we eliminated, downvoting became more important, not less, because individual upvotes were then able to pay out significantly without any sort of stake consensus.