Well if some ancient tribe did it well before the age of modern medicine and science, I'd say they must have been onto something and I should do it too.
The Jews, since the days of Moses which was many thousands of years ago, were well aware of the existence of germs, thus their insistence of washing your hands if you touched a dead animal or any blood or faeces. It wasn't until the mid 1800s that modern science said they existed, and prior to that, doctors happily did not wear gloves and worked between diseased and healthy patients without washing their hands. The idea of 'invisible' germs would have been laughed at and it took a brave doctor to make the connection.