brightj – thanks for pointing it out. This behaviour was supposed to be removed, but stayed. It will be removed in few minutes.
The original idea was that, in apps like OsmAnd, Maps.me or Mapy.com there is usually visible only the first website tag. By adding a link to OpenClimbing, users can easily find all the related links (also climbing:url:*) and see the image topo. Otherwise, they wouldn't know that they can combine the type+id with the OpenClimbing domain.
Of course, such behaviour should only happen with the contributor's consent – or perhaps when editing the topo itself, which adds information overlay not available elsewhere (yet).