He's 100% right.
I can't think of a single thing I've ever written that didn't have some threat of physical or emotional pain attached to it before it finally squeezed its way out of my tiny little brain. But I also think this is optimal for me. I don't operate at my "best" until I get out of my own way and let the work actually flow. To completely butcher something Jeff Buckley once said: it's only in the 4th quarter when you're exhausted that the moves you make are pure and from your soul. You're not thinking anymore, you're just acting and reacting, and that's where we determine what we're worth.
I'm always in the 4th quarter. Which is why half the shit I write, say, think or do comes out all weird and desperately needs editing. But it gets out there, dammit.