First, hello and Merry Christmas.

I believe that the existence of negative votes doesn't imply decentralization if the majority of network members don't use them.

If in a country only one person votes and chooses themselves, I don't think that country can be considered democratic because there are free elections and everyone can vote. The president of that country only represents the will of one person. That population doesn't assume the responsibility of choosing.

I used to think differently. I believed that if the network had approved a proposal for Hivewatchers to set their own criteria, investigate, judge, and punish if necessary, only Hivewatchers should carry out those tasks. I changed my mind because that would create a centralized network.

You mentioned several reasons why you would give negative votes. They are acceptable, they are reasonable. I also agree that they are your criteria and that they can change over time.
So the negative vote you cast does have a basis that goes beyond simply saying "I don't like it."

It's not mandatory to explain why you gave a negative vote. Otherwise, Marky should propose opening a customer service office. But if you kindly respond to the person who received the negative vote, I think it's appropriate to state the real reason and not resort to a "low-quality" response, which is what causes you to consider it a low-quality post. Although, I repeat, responding is not mandatory.
If you are kind enough to explain why you gave a negative vote in a particular case, based on your subjective experience, the explanation takes on an educational role and adds value. We learn both ways online: through hard knocks or through both education and hard knocks. The author also evolves.