The BIGGEST Writing Mistake(s)

You've probably heard people discuss "the biggest mistakes writers make," or even "THE biggest mistake (singular) writers make." Maybe you've heard some of the following named as that big/biggest mistake, and I think they do all vie for the position.

• The biggest mistake writers make is not knowing what a story is. I run into a lot of beginning writers who think an incident is a story. Or that an idea is a story. Or that, even, the plot is the story, which sounds truer, but I would say this: the story is the character growth. It's how the MC changes as a person after she's taken her goal or desire, battled all the odds (gone through the plot), and arrived at win, lose, or draw. At any rate, a story is more than "This happened, then this, and then this; the end," even if the sequence of events is amusing or really happened.
• The biggest mistake writers make is not realizing it's about the writing. As a teacher, I see good stories paired with so-so or outright weak writing WAY more often than I see wonderful writing and a weak story. In fact, I can't think of when I've run into the latter. I've found that top-notch writers will have a good story, too, maybe because their excellent writing helps make their story great. But merely having a good story predicts nothing about the level of writing.
• The biggest mistake writers make is not persevering. On the surface, this one almost needs no commentary. Most beginners have no idea how much work and time they're signing on for, either to learn the craft or to get published, and they have to slog through both. Honestly, though, I think some should quit. There's no shame in giving it a try and deciding it's not for you. That's true in any pursuit; why not also in writing? Yes, writers make a "mistake" in quitting too soon when they otherwise might have made it, but I think most writers who remain writers and really are writers simply cannot quit. In a sense, they cannot but persevere, so I look slightly askance at this "biggest mistake" claim.
• The biggest mistake writers make is not writing. No doubt: this is a biggie. Writing requires, wait for it...actual writing. If everything else in your life comes first, and you want to make significant progress as a writer, you need to switch things up and give writing a high priority in your life. My opinion is that it needs to be no lower than 4th, assuming the first three are God, family, and day job. I've said this elsewhere, but "God" is not equivalent to "church work." "Family" is not equivalent to "satisfying their every whim." And this does mean housecleaning and all that other good stuff rank from fifth place on down.
• This one might be my favorite, and it partly stems from the one just above: The biggest mistake writers make is to consider writing "something I do for me" instead of "career development like any other." Yes, I believe the biggest mistake is a wrong mindset. If you want to write and publish as a career, you can't think like a hobbyist. Agents and publishers don't take on hobbyists. You have to be as serious about your writing as your next-door neighbor is about getting her nursing degree. The Bible says that as we think, so are we. So I want to think right.

What do you think about these? What mistake(s) do you think are a writer's biggest?