Sorry to flog a dead horse here, but if you click on the link you very kindly provided, you see seven buttons given to sort the search results against. Those buttons are: Author, title, date updated, wordcount, date added, hits, and bookmarks. Hitting "bookmarks" produces exactly the result I'm complaining about.

I realise that this is a highly personal peeve and it probably doesn't matter two hoots to anyone else but I really do find it offensive (and the difference to Pinboard, etc, is that those aren't logically associated with the fic, so they aren't rubbing the author's nose in it the way the AO3 bookmark tags are). YMMV, of course, and I've spent too much time on this already but if there was going to be any top down look at the tagging system I just wish people would address that.

But since there doesn't seem any real likelihood of sorting anything out on this one any time soon it's probably just one of those things.