liz_marcs just brought up fanfic authors who will reply with a "I'm not trying to be a professional writer, I'm just a fanfic writer" when you point out a legitimate problem with their grammar or other work. This reminded me of another pet peeve excuse of mine.
"It's okay that I'm making this same terrible mistake over and over again, [Shitty Published Author] does it all the time!"
Being published does not mean you're actually a good writer, nor does it mean that you should be emulating their faults. Go pick up the Star Trek Novelization and try to count how many times the author decides to use a
Burly Detective for Spock instead of his actual goddamn name. I thought I was going to blow my brains out, trying to read that.
If you want to be a writer, try to be a good writer. That is all.