The data in OSM really does not need to be understood by everyone! If that was a rule it would take only a single really stubborn person to refute all our data, by insisting on not understanding it :-)

Did you (try to) understand the data before deleting? What part of it did you not understand,? If you are unfamiliar with the term spur, maybe the illustrations on page 18 of https://orienteering.sport/iof/rules/control-descriptions/ will help.

I'm open for better tagging, but simply deleting information because you don't understand it is not productive, I think...

I have indeed searched the wiki before adding, and found no relevant tags. It would be counterproductive to map this spur as a rock (as you seem to suggest?) when there is no rock. Or as a hill, when there is no hill, etc.

Kind regards.