Please implement something to teach players how to play

[Shurrikhan]

Because you did not make the rules, you did not make the ground. In what standards do you have a right to tell others how to play in said content?

The content accessed through the DF is still a known medium, a form with a given design, situated in a certain way, from which it takes on expectations according to that form and situation. It does not matter that the people are random; the setting for their interactions is neither novel nor random.

Consider the public interactions example. Even if it were somehow absent of danger, I could expect more from others driving beside me than meandering across lanes, stopping per their fancy anywhere and anytime, etc. Even if it did not waste my already meager time to buy food, I still would not appreciate someone else's child running headlong across the deli counter. Even if there were no trauma possible, I would not appreciate someone entering a conversation just to, through blatant lack of tact or compassion, sour everyone's mood. And one can obviously judge or channel their own actions accordingly. One need not make the "rules" -- though even that is too strong and too inflexible a word -- to have an understanding and appreciation of what behaviors do or do not burden others.

Dungeons as reached through the dungeon finder are still a setting which at the very least gives incentive and situation for certain behaviors, from which one may infer how they are meant to be interacted with. If one's behaviors are clearly at ends with its systems of situation and incentive, those they are burdening have every right to complain.

Yes, there are limits, lest the burden simply swap from one's access, in being able to do what content they want within the reasonable limitations of their available time and skill, to another's enjoyment, in being able to interact with the content in a particular way (that is still at least reasonable given how that content is situated and its incentives managed through design). But there is no hard rule of "if random, be mute".