Having slept on it, I think I can offer a more fine-grained explanation for what I think is going on.

There are implicit and explicit speech acts. You can implicitly or explicitly threaten someone, or compliment someone, or express romantic interest in someone. There are some speech acts which you cannot, or as a matter of policy should not, carry out implicitly. As extreme examples, you cannot implicitly extend someone power of attorney, and you should not interpret someone's implicit expressions of interest in being erotically asphyxiated as an invitation to go ahead and do so.

I believe implicit requests for advice basically shouldn't exist. I would expect social decorum to drive people's interpretations away from this possibility. Out in the big wide world, my experience is that people are considerably more careful about how they do and do not offer advice. My consternation is that on LW there appear to be forces driving people's interpretations towards the possibility of implicit requests for advice, which runs counter to my expectations.

Not what-the-fuck-are-you-doing counter to my expectations, I should point out. I might, for example, occasionally expect relative strangers at work to wordlessly take a pen from my desk, use it to scribble a note and then put it back. This is probably the most mildly-invasive act I can think of, but if I was disrupted every five minutes by someone leaning in and pinching one, stopping a wordless pen-borrower in their tracks and saying "seriously, what is it with the pens?" seems like a reasonable line of inquiry.

I'm not precious about my pens, (nor do I think I'm especially hostile to receiving unsolicited advice) but there are good reasons to have social norms that drive people away from this sort of behaviour. When those social norms cease to exist, those good reasons don't go away.