Generally places stress work life balance because the organization doesn't actually afford its members a work life balance, so the perception of it existing has to be constructed through propaganda.
i.e. If you already have work life balance, there's not need to stress it.
This is completely wrong. In our area (Silicon Valley) it is common and expected to push hard and work long hours. It is an extremely competitive environment and unless you're forced to go home most people work late into the night.
Not making an effort and letting your employees know that you don't expect them to work nights and weekends means you are ignoring the societal norms in our field and most likely have engineers working their way towards burnout.
This is just not true. Tech culture is rife with long days, nights, and weekends. In my experience, companies that truly care about work life balance often have to remind people of this just due to the fact that so many people are used to this culture and often have a difficult time escaping the mindset.
i.e. If you already have work life balance, there's not need to stress it.