[scubbo]

> Most people tolerate them out of sheer politeness

You are projecting. Some people are flattered to be a trusted confidante or emotional support, and glad to be able to help someone they care about. This is situational and dependent on factors (if someone's emotionally leaning on me every second of every day, it's going to get tiring pretty quickly), but even if the experience of the conversation _itself_ isn't exactly pleasant it might still be considered a worthwhile discomfort to go through for the emotional closeness generated (as a parallel - physically exercising isn't (often) pleasant, but the sensation afterwards and the physical well-being generated are considered worthwhile, so the activity is net-desirable even if it's unpleasant in-the-moment). In fact, apologizing for the act might insult the listener, implying that your relationship isn't strong enough to warrant such sharing. Further, the listener might care about the speaker's mood and state of mind so much that, even if the experience is net-negative _for them_, they're still glad to be able to provide that support to someone they love.

This is all subjective - you and your partner might so dislike being vented to, or feel such negligible positive effects from it, that the calculus ends up negative and an apology _is_ genuinely warranted. But it's not necessarily true for all (or even, I'd guess, most) people. You're right that avoiding imposition is good manners, but it is not necessarily the case that sharing feelings with someone is an imposition on them.

[thegrimmest]

Leaning on someone for emotional support unprompted is an imposition, just like relying on someone for financial support. Yes in some cases the imposition is welcome, and fosters closeness and interdependence, but in most cases it is better to be self-sufficient (emotionally and financially).

You'd surely apologize when asking even the closest friend for financial support, why not when asking (or worse, demanding) emotional support?