But, being a partner at Y Combinator, it's in your interest for the founders of the companies you're invested in (especially the newbies who would need this advice) to not have a very great work-life balance, and that's who your article was targeted to.
Maybe I read too much into it, but some of the points are so obviously not work that I have a hard time believing anybody would think they are. It made the whole article come off as, "You shouldn't be screwing around, you should be toiling away at your startup."
It's definitely not in my interest for the founders I've invested in to have bad work-life balances. It's not in my interest because I like them and care about them as humans.
Even if you were to assume that I was motivated exclusively by profit (which I'm not), then it would still be in my best interest to help founders find good balances. In that world, I wouldn't want them burning out, which is what happens when there's no balance.
I've seen founders and friends do everything on this list and call it/justify it as work. That's why I wrote the piece.