That is all I can figure is happening. I don't see it happening on sink strainers in restrooms where the plumbing is old and original. I see it in laboratories where research is done and lab water is used. Water that is highly filtered is hungry to get dirty again. The other thing I see is the chemicals that are added to water supplies are pretty tough on plastic and rubber parts in faucets and Sloan flush valves and Back flow preventers. The rubber gaskets swell up. The gasket on a Sloan valve angle stop will swell up and come off the part it is held on and get inside the valve and then it won't shut off.
I'm no genius when it comes to plumbing, but I have been doing it for about 32 years. I was a plumber at Purdue University for 22 years and now I work at the ASU Tempe campus at night. Been there since August of 2000. I just love being award to the state! If there are less than six plumbing problems in a night you are doing good. Some nights it seems like the whole campus is falling apart. And when it rains?! OH MY GOD! I hate it when it rains. Lots of roof leaks!