My experience is much different. I still get laughed at sometimes for using gloves, disinfectant and hand sanitizer. I know guys who think it's funny to do things bare handed and gross people out, like ignorant teenagers who think they know it all. They go by the idea that since they have never gotten seriously sick, they never will. I will spray down the steering wheel of a vehicle that I have to drive, other than my regular van, especially the drain cleaners, much to their amazement.Due to our exposure, many plumbers have strong immune systems and they know it.
In spite of this, I think plumbers for the most party have a good understanding and healthy respect for the germ theory of disease and take precautions (eg., gloves, soap and water).