Those and the endless duplicate submissions of the same story, by people too lazy to spare the couple of seconds needed to check whether it's already been submitted [often several times!].

I browse HN by the '/newest' page, so every time something hits the news I see it repeated over and over again on the first few pages. Even though people assure me that the HN software filters out duplicates, it's simply not true

As regards the spammy and/or junk submissions; I use a TamperMonkey script that allows me to add domains to a blacklist and sets those submissions to 'display:none'. So that allows me to pre-filter what shows up on the page.