Just because a lot of "startup people" binge drink doesn't mean all of them do. Dress right? Startups have a much freer dress code (read: they don't) than basically all traditional jobs. Most jobs have actual dress codes.

Also, having a family doesn't mean they are excluded based on their background. It means they have decided to value something above starting a company, something they are free to do. You translated "welcome people of all backgrounds" into "allow people to get exactly the same lifestyle and compensation format while also working at a startup." Anyone can start a startup. That doesn't mean everyone should or will.