People should know what they're getting in to, is the reason someone like Chris Dixon takes the time to write a post like this. He's not demanding that people not dip their toes; he's just saying, "I've been in the water, and it's fucking frigid".

He's right, from what I can tell. I've done my whole career in startups, and ~6 years into this one it's still costing me significant sleep and cortisol.