Humans being humans can’t compartmentalze and seamlessly switch back and forth between work mode and non-work mode. Besides, they spend the best 8-9 hrs of their creative period of the day at work so the happenings of outside world will be subconsciously analyzed at work.
If a black kid has been killed by a cop the previous night the injustice of it all will linger on for a few days whether at work or outside of it.
There are always external factors that can temporarily decrease work performance, like the death of a loved one. Those random dips are evened out over the workforce.
When large swaths of a business's employees can't even at work whenever there's tragic news, that becomes a problem for the business itself.
My point is even perceived discrimination imposes real economic cost.
If a black kid has been killed by a cop the previous night the injustice of it all will linger on for a few days whether at work or outside of it.