
...and why exactly do you believe these details are being added with the expectation for you to respond to them? That type of magic mindreading would be godmodding/metagaming. Rest assured, I'm sure the other RPer is not expecting your character to reply. As Katanyae mentioned, there is no "RP Rulebook," and sometimes you can sense/see how another person is feeling.
If someone mentions their character's inner thoughts/feelings, it's not necessarily so your character can notice. It's more often because the other RPer wished to share those details with you--the RPer, not your character. I usually find it enjoyable to know things about another person's character that aren't transparent, that my character doesn't realize. It's dramatic irony.
While you may not like it, there's really nothing wrong with it, so long as you have enough self-control and awareness to stop yourself from metagaming. The only way I see this as a downside is if someone's "inner monologue" goes on and on for paragraphs, or if the "inner monologue" is almost the entirety of the post, thus giving you no action or dialogue to respond to (in which case, the person probably doesn't know what to write, so they're just BSing about their character's thoughts).
In a novel, the main character's thoughts and feelings are not given because other characters in the story will respond to them. They're given so that you, the reader, may feel closer to the character and understand more about him or her. You may not be writing a novel in RP, but the same logic still stands, which sort of throws the "you're not writing a novel" argument out the window in this case.
TL;DR: I don't think most people are doing this in hopes of being "acknowledged" to begin with.
If someone mentions their character's inner thoughts/feelings, it's not necessarily so your character can notice. It's more often because the other RPer wished to share those details with you--the RPer, not your character. I usually find it enjoyable to know things about another person's character that aren't transparent, that my character doesn't realize. It's dramatic irony.
While you may not like it, there's really nothing wrong with it, so long as you have enough self-control and awareness to stop yourself from metagaming. The only way I see this as a downside is if someone's "inner monologue" goes on and on for paragraphs, or if the "inner monologue" is almost the entirety of the post, thus giving you no action or dialogue to respond to (in which case, the person probably doesn't know what to write, so they're just BSing about their character's thoughts).
In a novel, the main character's thoughts and feelings are not given because other characters in the story will respond to them. They're given so that you, the reader, may feel closer to the character and understand more about him or her. You may not be writing a novel in RP, but the same logic still stands, which sort of throws the "you're not writing a novel" argument out the window in this case.
TL;DR: I don't think most people are doing this in hopes of being "acknowledged" to begin with.