Bad treatment that cleaners received for nothing

I just don't get it why does cleaning stuff have to be treated so badly in front of everyone to witness it, and yet nothing is done by that. Earlier today a white lady at the center out of nowhere showed case by hauling and screaming at the cleaner, yet as I walked out of the bathroom everything was clean n spot on as usual... I'm failing to understand why did she scream like that.. I'm so unsettled by the treatment I feel sorry for the cleaners if that's the treatment they getting... I'm rating their job with 5stars... Something must be done