That’s an interesting idea, but how is it a “Reddit competitor”? Reddit isn’t primarily a shared annotated bookmarks site; this wouldn’t be in even approximately the same space as Reddit.
The idea that this is sufficient to deal with spammers is naive
1. Users can add links with tags 2. Users can upvote links 3. Users can curate their own set of links 4. Users can subscribe to other's links 5. Search can search on a combination of links, link content and tags
A modernized Delicious but crowd source relevancy without the need for moderation. Site becomes go to place for search in the same way I often get better results searching HN than Google for specific tech related items.