Comments on Reading Tonight

I've always wondered how much authors being married and cohabiting with another author influences them. I asked Nicole Krauss and she got offended (I may have worded my question badly, I was slightly drunk). Zadie Smith just said that her poet husband didn't really affect her writing at all (except that the title of her last book was from one of his poems!!) Shouldn't this be a McSweeney's issue? Why hasn't Steven Dixon written a 400 page novel about this?