Listen In - The Unwritten Rules of Fishing Etiquette - Audio Article by Dennis Vander Houwen 

When I have these encounters (similar to the one you described), I must admit, it can be difficult to exercise patience. Thus far, I haven't had any interactions go south. It's almost always the case that the offending person/people are clueless, very casual, novice fishermen who view fishing as a purely social activity and don't care if they catch fish. I have to remind myself that most people don't take fishing as seriously as I do, and that's ok. I also remind myself that these people could be at home getting drunk or high, but instead, they're outside doing something healthy. When my spot is invaded by these "newbies", I choose to look at it as a chance to challenge myself and explore new territory. I have found some of my best spots and made some of my best catches by simply moving away from the encroachers 🙂

Whenever someone talks about "unwritten rules" I remember the reason why they are unwritten: they are not rules, they are shit people make up in their head. (Apart from the picking up trash, I'm with you on that one)

unwritten rules of humanity dont walk behind someones ass when they are fishing give everyone space in a big ass forest .... people are npc zombies in general nowadays.