My company has always pretty explicitly discouraged working nights or weekends, though obviously some people will always end up working more because they want to.
While burnout and recruitment are both good reasons (you don't want core people to burn out and leave, and people don't want to come work for a bunch of slave-drivers), the less-often-cited reason to not work "harder," and one of our explicit motivations for it, is because often times saying "we'll just work harder" prevents you from having to make tough prioritization decisions, and that can mask bad decisions that have been made and that are costing you time.
As with all rules, there are exceptions, and there are times when you just need (or want) to crank hard on something. But in this case, we've found that the constraints imposed by working normal hours helps to improve your decision making and focus your priorities.
While burnout and recruitment are both good reasons (you don't want core people to burn out and leave, and people don't want to come work for a bunch of slave-drivers), the less-often-cited reason to not work "harder," and one of our explicit motivations for it, is because often times saying "we'll just work harder" prevents you from having to make tough prioritization decisions, and that can mask bad decisions that have been made and that are costing you time.
As with all rules, there are exceptions, and there are times when you just need (or want) to crank hard on something. But in this case, we've found that the constraints imposed by working normal hours helps to improve your decision making and focus your priorities.