Earlier quoted context omitted.
It is ok to share your own stuff. I mean, look at the submission history of the guy you are responding to ;) minimaxir posts tons of his own content, but it is good content, and he also participates on the site otherwise. Also, agreed with CarolineW. Show examples.
The key word the OP mentioned is only : Here is his example account: https://news.ycombinator.com/submitted?id=grisanik All submissions are from one domain, and there are barely any comments.
a) none of these got any user engagement (ok, some got an upvote or two and a single one actually managed to attract a comment)
b) despite this, there is a constant stream of several submissions per week
c) the user didn't comment on other articles, but just "dropped off" their content
EDIT: regarding the last edit: I don't care for Musk-news either, but if it is not spammed and not duplicate I have no reason to flag it, and apparently enough people care to upvote it. I upvote if people submit something cool they made. Others do as well, the stuff many people find cool rises. "I just added a tiny boring feature to my boring app", not so much.