GMs and Players should consider each other human beings, find common ground, and move forward or not based on that. That's just because in all my years I've found the person not willing to listen is usually the one in the wrong. That and fucking everything has nuance to it.
"I don't want rape in the game" is a valid statement that really doesn't require follow up. I think the only person who would need an explanation for that one is a sick person who doesn't understand the severity of that crime in every sense of the word severe. If as a GM you can't get around that prohibition, there might be something wrong with you. In fact, more later.
"I don't like spiders, so no giant spiders" is fucking silly. I can't think of an situation where I wouldn't laugh the person making that statement out of the room. It'd take a full blown discussion to change my mind, and during the discussion we'd say the word "spider" enough to invalidate the argument of the one making it against me. So again, I can't think of a situation where it isn't asinine.
These both prior paragraphs make sense and are not in any way mutually exclusive. Your brain is broken if you think one is right and the other isn't right.
My central problem with "mature content" is that it's very very often handled/executed immaturely. Being in my late 30s and a connoisseur of garbage cinema since before I can remember, "mature content" is generally blah now. It reminds me of a 14-year-old painting their nails black and jotting down Cannibal Corpse lyrics in their spiral bound notebook in Biology class. I began watching hard R - 70s and 80s horror movies - when I was in single digits because I had insomnia and HBO. After midnight in the 90s, HBO was trash movie central. I sorta grew up and out of that stuff. Nowadays I consider it a shortcut, substituting shock for substance because that's what they did in movies in the 70s and 80s. It's like Death Wish happened, then literally every revenge action movie thereafter required having the big R, and often gratuitous minutes of it, as a plot point.
I tend to run my games as PG-13, but an 80s Spielberg PG-13. I try to get the general tempo/maturity of my games to Saving Private Ryan or Apocalypse Now, usually it's closer to The Fifth Element or True Lies. I know the former are R-rated movies, but they are legitimately mature films rather than a Troma R-rated trash because curse words, nipples, innuendo, half-orc conception, and poop monsters. I mean, it can't be just me. Doesn't that shit seem angsty-teenagery?
