Looking over the jobs pages of some of these companies it's interesting to note how many of them expect you to make your new job there "the primary focus of your life". For instance, go google for

"primary focus of your life" intitle:jobs

and you get:

Quora: "You should be ready to make this startup the primary focus of your life"

Udemy: "You should be ready to make this startup the primary focus of your life"

GoPollGo: "you should be ready to make working on GoPollGo the primary focus of your life."

Bubbli: "you should be ready to make Bubbli the primary focus of your life."

So yeah, probably not a good fit for someone with a wife and kids.