Had it happen a few times unfortunately. They had a good first impression on me with the comic in one thread, then in the next they're being very rude, bitter, offensive or all three. No faster way to make me close that tab.
Outside of the forums it's happened less, but it's usually binging a few pages, looking at their social media/Author's Notes, and it's someone going "woe is me" and basically grilling their readers for not promoting it enough. Don't do that, please
Also, best way to get me to stop reading your work that happened in here and out of here: namedropping other people's works to talk poorly of them. Criticism is fine especially if the work did something heinous or squandered potential, but if you're going to be gossiping about other creators like it's a competition, I've got better stuff to read.