How does a chain get filthy and how can you stop it from getting filthy? For the record, my chain looks a lot filthier. I hate cleaning bikes beyond anything. I don't clean my training bike very often, because it's only got cheap compenents and I do not care much if they don't last very long.

All that filth has to come from someplace so I was wondering if someone could specifically suggest from where, how and from what direction all that filth emigrates onto my chain and why it chooses to stay there. And then maybe I, or anybody else, can come up with a genius idea of how to stop the filth from making it's way onto my chain in the first place so nobody will ever have to clean it again.

Something like this maybe. You get the idea.
The "filth" is a composite material. It is a mixture of chain lube, road grit, and the metal filings from gear and chain wear. The road grit is composed of sand, tire bits, asphalt, trash, etc. The issue is when you mix them all together it forms a thick, pasty sticky mess.. The goop tends to collect more material. The  grit in the sticky residue acts like sandpaper accelerating wear. You can minimize but not eliminate it by using the correct lube. This generally means a dry type lube when the conditions are dry and a wet lube when the conditions are wet.