Since when is naivety negative? You are born without knowledge. You acquire knowledge throughout existence. Seems pretty natural to me.

It's unpleasant to accuse someone of being naive in a paternalistic fashion that implies "you're wrong, because you don't know any better, but if you knew better you'd agree with me".

The post you replied to embodied a preference. You responded that they were wrong and naive for not wanting to depict cities constantly "being pulled into the ground". Some people playing a simulator do not want the simulator to force unavoidable decay everywhere. This is something for which there is room for a breadth of preferences, not something for which there is a correct and incorrect answer.

The state of being naive is not negative.

The presumption of someone assuming "I think I am right and you are wrong and therefore I declare you to be naive" is a negative one.

There are many traits that is perfectly fine to possess, but extremely rude/arrogant/negative/etc to declare as existing in someone else.