The bigger risk for deletions seems to be not tech related stuff but rather non-tech related stuff that manages to get a couple of upvotes.

HN is social news simply because the audience can define it as such.

The main ingredients, the ability to post links and to discuss them and to revisit them at a later stage makes it such that some users will come by and use it in that way.

All the stuff you submit and upvote goes on that list, you can't remove stuff from the list if you've upvoted it, you can't remove stuff from the list after a certain time has passed.