Here's a tagline of a review from the Toronto Star: All literature comes to us courtesy the geeks, misfits and outlaws Happy, nice people don't become artists, writes John Terau
Oh, pish. I'm a happy, nice person, and I'm a writer. Okay, yeah, I'm also a geek. I'm not a misfit only because I've found someone to fit with. And it's possible that I'm deeply, intensely, Flannery-O'Connory odd -- I wouldn't know. But none of that keeps me from being happy. In fact, it makes me happy. So cut it with the sweeping silly judgements.

I think you may have failed to spot the false dilemma in the statement. It's perfectly possible to be a happy, nice, geek, misfit and/or outlaw.
Yeah, I'm just sensitive to the insinuation that Writing Will Ruin Your Life. Well, not so far, but being a poet I fear the power of repetition.
The editor who wrote the tag didn't get it either; I think the reviewer's idea (to the extent he had one) was more that interestingly unhappy folk make better subjects for literature than boring happy ones. That's false, too, but there's enough truth in it to make problems.
You bet. It's a real disadvantage to have had a happy childhood.