The complete lack of context on why a given decision was made causes frustration for the community and fails to educate people.
In this case, you could have added something like “because the subject of the nomination, the artwork, no longer recognizably exists at this location, and while we have no published guidelines on removal criteria or when it would be repurposing to update an existing wayspot, the object no longer meets our criteria as unique art.”
Relying on the community to explain why you have made or will make a given decision allows false statements to proliferate as users guess at prior decisions and treat them as new criteria statements not made or clarified elsewhere.