goodidea
There have been public accessible steps until 2002 (as the description in german says…), but this way was abandoned and closed by the city government (therefor it is tagged with access=no and abandoned=yes), but the steps still exist (and neighbours pleaded to reopen it again as far as I know, but it will stay closed I think). 

Because the steps still exist (under plants as you wrote and perhaps not in a good condition) and because it will be reopened again (although it's unlikely to happen) the way still exists in OpenStreetMap. I think it is OK like it is. That's why I closed this note now ...