A number of people at Stripe have families or have other social attachments. We try hard to ensure we're not making lifestyle assumptions when we hold social things. Some of this involves giving good advance notice, other times it's around timing. Trivial example: recently, we moved an internal talk series from dinner time to 4pm, so that people who don't stay for dinner aren't excluded. I think explicitly keeping things like that in mind helps.

But this would eventually converge to the 9-5 frame of things, wouldn't it? This is the only time of day that everyone is absolutely certain to have no other commitments other than working.

Also, the fact that you had the talk initially set for the dinner time basically means that your culture is already incompatible with the lifestyle of those who value family over work. I am not saying it's a bad thing, I used to actually sleep at work when I was younger, but it is an indication of problems you'll face once your team gets over a certain size. Diversity has a smaller common overlap.

I'm married too (no kids yet) and have a long commute. Most of my colleagues are single, male in the 23-30 age demographic and live in the city. They obviously go out way much more than I do. Family is important to me, but every once in a while, I make a conscious effort to socialize outside of the work environment. I do think that socializing every once in a while is important to build camaraderie among colleagues. Of course, when booze is involved (more often so than not), people tend to loosen up a bit and chat more openly. Even if you have a family, I would suggest making time once a month to socialize (be it a social events@work or other professional meetup events).